93 LT1 to LS1 Wiring Harness Conversion How To
05-31-2009, 04:13 PM
#1
Launching!
Thread Starter
iTrader: (3)
Join Date: Jan 2009
Posts: 212
Likes: 0
Received 0 Likes
on
0 Posts
93 LT1 to LS1 Wiring Harness Conversion How To About the 1993 LT1 F-Body
The engine harness is somewhat similar to the LS1 engine harness in the way it connects to the vehicle.
There are basically three connections under the dash:
* C210 (see attached 93LT1_C210.gif)
* C220 (see attached 93LT1_C220.gif)
* C230 (see attached 93LT1_C230.gif)
There is one connection near the PCM that, for the most part, runs to the fuse block under the hood:
* C100 (see attached 93LT1_C100.gif)
About the 2002 LS1 F-Body
There are two connectors under the dash:
* C210 does not exist anymore (see notes below)
* C220 (see attached 2002LS1_C220.gif)
* C230 (see attached 2002LS1_C230.gif)
There are three connections near the PCM:
* C100 (see attached 2002LS1_C100.gif)
* C101 (see attached 2002LS1_C101.gif)
* C105 (see attached 2002LS1_C105.gif)
The only tool I think you’ll find handy is at http://www.eficonnection.com/eficonn..._junction.aspx, bottom of the page. This green terminal removal tool will allow you to easily remove terminals from any of the connectors mentioned above.
The swap is pretty simple just time consuming the harness took me close to 12 hours to do but it was well worth the experience and knowing how the car interfaces with it.
The only things you need for the wiring harness is:
A 98 Water temp sensor with analog output for the water temp gauge its a TPS type connector.
A C210 Connector to route the starter relay power and constant battery power to the ecm.
Extra 12 gauge purple wire for the starter wire. Extra white, pink, orange, dark green/white wire and I think thats it for wiring.
You will also need an OBDII connector for diagnostics.
There is one more ignition circuit on the LS1 that is not in the LT1. The circuit 239 in the 93 is for the opti but in the LS1 is for emissions dont remember if its air or what. Basically I rewired this 239 circuit from the 93 into 539 of the LS1 which is for heated o2's which was not available in the 93. 539 is also for other engine sensors you will need to replace fuse 7 with a 20 amp fuse instead of 10 can't remember which fuse block.
Also you will need to repin C220,230, and 100. 105 and 101 are not applicable but the extra wire I told you you needed is to lengthen some wires from the 100 connectors to go to the 200 series. All the connectors will interface with the car its just not pinned right.
The AC system functions the same and does not have be to messed with. The engine speed signal is a white wire that needs to be lengthened from 100 series into the 200 and also you need to wire the fuel relay (for some reason this did not work for me the system is wired different and the LT1 uses two fuel inputs one circuit is a prime circuit the other is run, the LS1 only has one circuit. If you use the gray wire it will prime the pump but not run it and the fuel enable signal does nothing just kicks on the relay from my understanding. For this reason it is needed to run the pump off a direct ignition source and not into the 200's. The constant power wire which is an orange wire in 101 or 105 I believe this is a 16 gauge wire or 18 not the 12 or 14 this needs to be wired into the 200's and must be lengthened. The bigger orange wire in 105 G can be removed its for an air pump which I personally deleted. The smaller gauge orange wire from earlier needs to go into C210 constant power for ECM. Also make sure the ground is wired in the C210 connector as it is the ground for you gauges.
All the 5v reference signals can be removed and crusie control. Since cruise control and fuel system is pretty much a separate singal except for the fuel enable signal from the ecm and the fuel realy control which is why the pump does not work using the new pcm because the fuel enable signals are different and there is also a fuel relay control. You will also need to turn vats off in the computer because the LS1 uses class 2 serial data and the 93 uses the serial data UART. The serial data UART does not need to be hooked up for the LS1 PCM to be happy and run.
Side Notes and references:
Starter Circuit
In 93 the 10ga purple wire that cranks the starter over ran through C210. The LS1 car did away with this connector and ran this purple wire from the starter, to a single metri-pack connector near C100, and then probably to a relay in the fuse block under the hood. You’ll need to identify this purple wire near C100 and run it under the dash and into C210, cavity A.
98 LS1 Coolant Temp Sensor
Analog output for gauge along with communication to computer. TPS connector.
Tachometer
Off by 1/2 corvette computers will not work with the LT1 tach.
The 93 HVAC system is very similar to the 2002 HVAC system.
* The only significant difference is that, from what I can tell, the LS1 HVAC system does not have an A/C Evaporator Temperature Sensor; a three wire connection under the dash into the evaporator. The LS1 PCM does not require this signal, so that means your evaporator temp sensor will remain unplugged.
The engine harness is somewhat similar to the LS1 engine harness in the way it connects to the vehicle.
There are basically three connections under the dash:
* C210 (see attached 93LT1_C210.gif)
* C220 (see attached 93LT1_C220.gif)
* C230 (see attached 93LT1_C230.gif)
There is one connection near the PCM that, for the most part, runs to the fuse block under the hood:
* C100 (see attached 93LT1_C100.gif)
About the 2002 LS1 F-Body
There are two connectors under the dash:
* C210 does not exist anymore (see notes below)
* C220 (see attached 2002LS1_C220.gif)
* C230 (see attached 2002LS1_C230.gif)
There are three connections near the PCM:
* C100 (see attached 2002LS1_C100.gif)
* C101 (see attached 2002LS1_C101.gif)
* C105 (see attached 2002LS1_C105.gif)
The only tool I think you’ll find handy is at http://www.eficonnection.com/eficonn..._junction.aspx, bottom of the page. This green terminal removal tool will allow you to easily remove terminals from any of the connectors mentioned above.
The swap is pretty simple just time consuming the harness took me close to 12 hours to do but it was well worth the experience and knowing how the car interfaces with it.
The only things you need for the wiring harness is:
A 98 Water temp sensor with analog output for the water temp gauge its a TPS type connector.
A C210 Connector to route the starter relay power and constant battery power to the ecm.
Extra 12 gauge purple wire for the starter wire. Extra white, pink, orange, dark green/white wire and I think thats it for wiring.
You will also need an OBDII connector for diagnostics.
There is one more ignition circuit on the LS1 that is not in the LT1. The circuit 239 in the 93 is for the opti but in the LS1 is for emissions dont remember if its air or what. Basically I rewired this 239 circuit from the 93 into 539 of the LS1 which is for heated o2's which was not available in the 93. 539 is also for other engine sensors you will need to replace fuse 7 with a 20 amp fuse instead of 10 can't remember which fuse block.
Also you will need to repin C220,230, and 100. 105 and 101 are not applicable but the extra wire I told you you needed is to lengthen some wires from the 100 connectors to go to the 200 series. All the connectors will interface with the car its just not pinned right.
The AC system functions the same and does not have be to messed with. The engine speed signal is a white wire that needs to be lengthened from 100 series into the 200 and also you need to wire the fuel relay (for some reason this did not work for me the system is wired different and the LT1 uses two fuel inputs one circuit is a prime circuit the other is run, the LS1 only has one circuit. If you use the gray wire it will prime the pump but not run it and the fuel enable signal does nothing just kicks on the relay from my understanding. For this reason it is needed to run the pump off a direct ignition source and not into the 200's. The constant power wire which is an orange wire in 101 or 105 I believe this is a 16 gauge wire or 18 not the 12 or 14 this needs to be wired into the 200's and must be lengthened. The bigger orange wire in 105 G can be removed its for an air pump which I personally deleted. The smaller gauge orange wire from earlier needs to go into C210 constant power for ECM. Also make sure the ground is wired in the C210 connector as it is the ground for you gauges.
All the 5v reference signals can be removed and crusie control. Since cruise control and fuel system is pretty much a separate singal except for the fuel enable signal from the ecm and the fuel realy control which is why the pump does not work using the new pcm because the fuel enable signals are different and there is also a fuel relay control. You will also need to turn vats off in the computer because the LS1 uses class 2 serial data and the 93 uses the serial data UART. The serial data UART does not need to be hooked up for the LS1 PCM to be happy and run.
Side Notes and references:
Starter Circuit
In 93 the 10ga purple wire that cranks the starter over ran through C210. The LS1 car did away with this connector and ran this purple wire from the starter, to a single metri-pack connector near C100, and then probably to a relay in the fuse block under the hood. You’ll need to identify this purple wire near C100 and run it under the dash and into C210, cavity A.
98 LS1 Coolant Temp Sensor
Analog output for gauge along with communication to computer. TPS connector.
Tachometer
Off by 1/2 corvette computers will not work with the LT1 tach.
The 93 HVAC system is very similar to the 2002 HVAC system.
* The only significant difference is that, from what I can tell, the LS1 HVAC system does not have an A/C Evaporator Temperature Sensor; a three wire connection under the dash into the evaporator. The LS1 PCM does not require this signal, so that means your evaporator temp sensor will remain unplugged.
05-31-2009, 04:14 PM
#2
Launching!
Thread Starter
iTrader: (3)
Join Date: Jan 2009
Posts: 212
Likes: 0
Received 0 Likes
on
0 Posts
Questions and Answers: Figured out some wiring issues i had.
I pretty much have my wiring figured for swaping my 93 A4 to a 2002 LS1 w 6 spd.
There is an orange wiring in connector C105 that says constant battery power where should I wire this in?? Should I splice this into the constant battery power to power the ecm and run them through C210.
This was emissions related deleted it and power circuit 239 because it was automatic and emissions relate (EVap) therefore the 539 circuit the LT1 doesn't have was wired into this location.
There was one circuit floating around 539 that was addressed it is the engine sensor power fuse. It was wired into LT1 circuit 239 which was for opti spark. BEWARE this was a 10 fuse link this must be upped to 20 AMP 15 might get by due to rear o2 delete and air delete but am still sticking with 20.
I also realized that there is a starter relay control coming out of C100 in the LS1 and I can not find a place for it. Can this wire be deleted or should I be wiring this to somewhere under the dash. This is not used the 93 uses a separate power circuit using a VATs Pass Keycode module along with tying into auto/manual neutral/park switch and ignition. This power wire is then linked directly from the positive junction under and out the dash on a 10 gauge i believe purple wire through connector C210 unique to LT1 cars.
Also what are the serial data lines coming from the LS1 that i should wire into the LT1 to keep the serial data functioning?? I found a dark green serial data wire but I can't find the tan wire which I believe it should be.Serial data is a kind of GM communication link that sends analog signals back and forth with a parallel connections both ends are terminated meaning the signal is grounded in the ecm after it was read terminating it and on the other end it was also grounded in the traction control or abs wherever it ends. This does not apply to the LT1 car though because it was serial (UART) which was an earlier type of communictions and the abs should function fine the TCS might still work but it will be unable to pull timing or close the throttle I am not sure how to get cruise to work I think i had it but my motor is fried so I dont know. If crusie works it should be able to close the throttle for TCS. The 2002 uses serial data 2 connection which is dark green or purple. This wire is only needed for obdII diagnostic the port connects with 2 grounds 1 power and the serial data 2 connection.
For the auto to manual trans swap. I can delete the TCC signal in the body connectors I believe because its only a ground but how do I get the reverse tail lights to work?? Is this simply tying the wire into the exterior light circut? Also do i move the park saftey switch to under the clutch pedal for neutral starting and vats to work? Last question for this is for cruise control is it possible to tie in the Clutch Anticipated signal into the brake signal to disengage cruise or do these signals function differently. The TCC signal cavities H and J C230 can be deleted they are only grounds for diagnostic purposes allowing you to lock the torque convertor clutch through the DLC to test it and for communication on when to lock.
The reverse tail lights are a lt green wire tied into a reverse indicator circuit on the shifter. It receives power from the I/P fuses. Its just a switch locate the green and brown wire in the wiring harness and remove the connector for the automatic and wire it into the existing brown wire and lt green wire in place already and just plug it in and the lights shoudl work. If the car was originally a manual just plumb it in through the C200 connectors.
To disengage cruise control there is a switch on the brake pedal that is a two way switch. It has three wires a a ground and the two powers I believe it is wired. One is activated off of the brake and the other lt blue wire ties into the hazard lights remove this and tie into the cruise disengage switch on the clutch pedal already. You cannot tie this into the clutch safety because the clutch safety defualt is open and the defualt for the cruise disengage is closed. The cruise will be functional now since it is a separate circuit with its own motor just tie it into the throttle.
Also can I delete air/egr/evap and rear O2's before getting my computer flashed and run the car for a while or do I need these flashed before I can run?Yes but probably wont run well and not applicable for 93 since it is an older model of passkey not using serial data class 2 and will not work without vats disabled. DON'T get this confused with disabling the alarm. All it does is allows the pcm to send the fuel enable signal without recognizing the key because the vats on the 93 is located on the car and recognizes a separate key (for the start circuit self-contained under the dash). It is your key only that can start the car still if you disable the vats on the pcm.
The vats system also does not have to be rewired to work correct?? If it was functioning before it still should now?? This was answered up but yes it will work it is a separate circuit. No rewiring necessary
I pretty much have my wiring figured for swaping my 93 A4 to a 2002 LS1 w 6 spd.
There is an orange wiring in connector C105 that says constant battery power where should I wire this in?? Should I splice this into the constant battery power to power the ecm and run them through C210.
This was emissions related deleted it and power circuit 239 because it was automatic and emissions relate (EVap) therefore the 539 circuit the LT1 doesn't have was wired into this location.
There was one circuit floating around 539 that was addressed it is the engine sensor power fuse. It was wired into LT1 circuit 239 which was for opti spark. BEWARE this was a 10 fuse link this must be upped to 20 AMP 15 might get by due to rear o2 delete and air delete but am still sticking with 20.
I also realized that there is a starter relay control coming out of C100 in the LS1 and I can not find a place for it. Can this wire be deleted or should I be wiring this to somewhere under the dash. This is not used the 93 uses a separate power circuit using a VATs Pass Keycode module along with tying into auto/manual neutral/park switch and ignition. This power wire is then linked directly from the positive junction under and out the dash on a 10 gauge i believe purple wire through connector C210 unique to LT1 cars.
Also what are the serial data lines coming from the LS1 that i should wire into the LT1 to keep the serial data functioning?? I found a dark green serial data wire but I can't find the tan wire which I believe it should be.Serial data is a kind of GM communication link that sends analog signals back and forth with a parallel connections both ends are terminated meaning the signal is grounded in the ecm after it was read terminating it and on the other end it was also grounded in the traction control or abs wherever it ends. This does not apply to the LT1 car though because it was serial (UART) which was an earlier type of communictions and the abs should function fine the TCS might still work but it will be unable to pull timing or close the throttle I am not sure how to get cruise to work I think i had it but my motor is fried so I dont know. If crusie works it should be able to close the throttle for TCS. The 2002 uses serial data 2 connection which is dark green or purple. This wire is only needed for obdII diagnostic the port connects with 2 grounds 1 power and the serial data 2 connection.
For the auto to manual trans swap. I can delete the TCC signal in the body connectors I believe because its only a ground but how do I get the reverse tail lights to work?? Is this simply tying the wire into the exterior light circut? Also do i move the park saftey switch to under the clutch pedal for neutral starting and vats to work? Last question for this is for cruise control is it possible to tie in the Clutch Anticipated signal into the brake signal to disengage cruise or do these signals function differently. The TCC signal cavities H and J C230 can be deleted they are only grounds for diagnostic purposes allowing you to lock the torque convertor clutch through the DLC to test it and for communication on when to lock.
The reverse tail lights are a lt green wire tied into a reverse indicator circuit on the shifter. It receives power from the I/P fuses. Its just a switch locate the green and brown wire in the wiring harness and remove the connector for the automatic and wire it into the existing brown wire and lt green wire in place already and just plug it in and the lights shoudl work. If the car was originally a manual just plumb it in through the C200 connectors.
To disengage cruise control there is a switch on the brake pedal that is a two way switch. It has three wires a a ground and the two powers I believe it is wired. One is activated off of the brake and the other lt blue wire ties into the hazard lights remove this and tie into the cruise disengage switch on the clutch pedal already. You cannot tie this into the clutch safety because the clutch safety defualt is open and the defualt for the cruise disengage is closed. The cruise will be functional now since it is a separate circuit with its own motor just tie it into the throttle.
Also can I delete air/egr/evap and rear O2's before getting my computer flashed and run the car for a while or do I need these flashed before I can run?Yes but probably wont run well and not applicable for 93 since it is an older model of passkey not using serial data class 2 and will not work without vats disabled. DON'T get this confused with disabling the alarm. All it does is allows the pcm to send the fuel enable signal without recognizing the key because the vats on the 93 is located on the car and recognizes a separate key (for the start circuit self-contained under the dash). It is your key only that can start the car still if you disable the vats on the pcm.
The vats system also does not have to be rewired to work correct?? If it was functioning before it still should now?? This was answered up but yes it will work it is a separate circuit. No rewiring necessary
07-14-2009, 03:25 PM
#6
On The Tree
iTrader: (1)
Join Date: Jan 2006
Location: fairhope, al
Posts: 183
Likes: 0
Received 0 Likes
on
0 Posts
i've got a question that you might be able to answer for me. when swapping an ls1 into a 93 lt1, from reading your info above it looks like you've figured out the gauge configuration.
engine rpm (for the tach) is off by 1/2 but how do you make it register correctly on the tach?
the coolant temp gauge is accounted for with the 98 sensor?
so im guessing: the fuel level isn't changing from the lt1 setup. the oil pressure gauge still works. the battery voltage guage still works. the speedo gauge still works (off of wheel speed sensors?)
thanks. i'd like to swap to gen III/IV technology but i don't want to have to buy a grand worth of autometer gauges. lol i know it's kinda an odd reason. but budget is key.
/hijack
engine rpm (for the tach) is off by 1/2 but how do you make it register correctly on the tach?
the coolant temp gauge is accounted for with the 98 sensor?
so im guessing: the fuel level isn't changing from the lt1 setup. the oil pressure gauge still works. the battery voltage guage still works. the speedo gauge still works (off of wheel speed sensors?)
thanks. i'd like to swap to gen III/IV technology but i don't want to have to buy a grand worth of autometer gauges. lol i know it's kinda an odd reason. but budget is key.
/hijack
07-14-2009, 04:07 PM
#7
Nice thread..I guess everyone of us has our own unique way of doing this. 
You will have to tune it for the Gauges to work correctly.
The 1998 LS1 Temp Sensor had 3 Pins..2 go to the PCM and the third goes to the Analog Gauges(1998 and back), in 1999 the Gauges were digital.
Nothing with the Fuel System has to be messed with on these LT1 cars, the only thing is the Fuel Pump Relay Signal and Ground in the Harness.
Oil Pressure Gauge signal is in the LS1 Harness, for a 1999 up LS1 Harness you will have to splice into the Alternator Signal wire for the Volt Gauge, the 1998 Harness has this in the Harness from the factory.
Speedo works from the sensor in the Tailshaft of the Transmission, same for both the Auto and T56. They send the signal to the PCM and the PCM has a signal wire that goes to the gauges.
i've got a question that you might be able to answer for me. when swapping an ls1 into a 93 lt1, from reading your info above it looks like you've figured out the gauge configuration.
engine rpm (for the tach) is off by 1/2 but how do you make it register correctly on the tach?
the coolant temp gauge is accounted for with the 98 sensor?
so im guessing: the fuel level isn't changing from the lt1 setup. the oil pressure gauge still works. the battery voltage guage still works. the speedo gauge still works (off of wheel speed sensors?)
engine rpm (for the tach) is off by 1/2 but how do you make it register correctly on the tach?
the coolant temp gauge is accounted for with the 98 sensor?
so im guessing: the fuel level isn't changing from the lt1 setup. the oil pressure gauge still works. the battery voltage guage still works. the speedo gauge still works (off of wheel speed sensors?)
The 1998 LS1 Temp Sensor had 3 Pins..2 go to the PCM and the third goes to the Analog Gauges(1998 and back), in 1999 the Gauges were digital.
Nothing with the Fuel System has to be messed with on these LT1 cars, the only thing is the Fuel Pump Relay Signal and Ground in the Harness.
Oil Pressure Gauge signal is in the LS1 Harness, for a 1999 up LS1 Harness you will have to splice into the Alternator Signal wire for the Volt Gauge, the 1998 Harness has this in the Harness from the factory.
Speedo works from the sensor in the Tailshaft of the Transmission, same for both the Auto and T56. They send the signal to the PCM and the PCM has a signal wire that goes to the gauges.
Trending Topics
07-14-2009, 05:13 PM
#9
No prob.
Here is my threads on this if anyone wants to take a look. All of us that do this have our own unique way..that's a good thing cause if one of us missed something the other will fill it in hopefully.
https://ls1tech.com/forums/conversio...o-lt1-car.html
https://ls1tech.com/forums/lt1-lt4-m...onversion.html
Here is my threads on this if anyone wants to take a look. All of us that do this have our own unique way..that's a good thing cause if one of us missed something the other will fill it in hopefully.
https://ls1tech.com/forums/conversio...o-lt1-car.html
https://ls1tech.com/forums/lt1-lt4-m...onversion.html
07-20-2009, 10:07 AM
#10
Launching!
Thread Starter
iTrader: (3)
Join Date: Jan 2009
Posts: 212
Likes: 0
Received 0 Likes
on
0 Posts
merv got it.the computer has to be tuned to send the correct signal.
All gauges work properly if hooked up and c210 is grounded.
You do have to splice into the alternator wire to get a volt. But the temp sensor will give the correct reading.
All gauges work properly if hooked up and c210 is grounded.
You do have to splice into the alternator wire to get a volt. But the temp sensor will give the correct reading.
07-21-2009, 08:25 AM
#13
Launching!
Thread Starter
iTrader: (3)
Join Date: Jan 2009
Posts: 212
Likes: 0
Received 0 Likes
on
0 Posts
I would definitely recommend bulding an 02 stroked ls1 but thats my 2 cents. The money saved in an iron block is not worth the extra stength and 70 pounds. I have a friend running a stock ls1 block over 1000 hp.
I still have mine for the time being.
I still have mine for the time being.
07-21-2009, 10:44 AM
#15
Launching!
Thread Starter
iTrader: (3)
Join Date: Jan 2009
Posts: 212
Likes: 0
Received 0 Likes
on
0 Posts
FTW??? You talking about weight?? There is a major weight difference which will already contributre alone to about a .1 decrease in trap time. Since 700 pounds equals a second.
07-22-2009, 10:19 AM
#16
On The Tree
iTrader: (1)
Join Date: Jan 2006
Location: fairhope, al
Posts: 183
Likes: 0
Received 0 Likes
on
0 Posts
well let's not turn this thread into an iron vs. aluminum arguement. i've had 2 ls1's and now have my first lt1. all 3 cars drive great. i, myself, would like a big cubed (larger than 383), durable (iron), motor that i can build up forged at around 10:1. eventually i'll take it the boost route. that's just my plan. any ltx or lsx motor will be outstanding, and i'm sure all of us can agree. that's why i'm not driving a rustang.
edit: ps. i'm not too worried about trap times, i don't really plan on racing the track every weekend.
edit: ps. i'm not too worried about trap times, i don't really plan on racing the track every weekend.
Last edited by blackhawk400; 07-22-2009 at 10:26 AM. Reason: ps.
04-28-2011, 05:48 PM
#19
Launching!
Thread Starter
iTrader: (3)
Join Date: Jan 2009
Posts: 212
Likes: 0
Received 0 Likes
on
0 Posts
Its easy just got to find what year and what info. Depending on year some wires might need to be lengthened. The tricky ones are the 2004-2006 GTO's a little more involved.
06-10-2016, 07:05 PM
#20
From what i have been reading this doesnt seem bad at all. I do have 2 questions though. Will a stock 5.3 be able to run on a 98 ecu and did you have to strip your harness all the way down or did you just locate the wires and try to move them individually?