87lsttop

iTrader: (2)

I have tried to come up with a write up on how to wire in a ls harness into a fox mustang. Most of the wiring is the same for most all the cars body harnesses.

This is what i have come up with so far. If any of the information is incorrect please let me know as i am not a electrical conteseur.

1. Fuel pump signal wire from fuse block- connects to Red connector pin 9 dkn green/ white
2. Pcm ignition supply from fuse block – connects to blue connector 19 and 75- pink
3. Pcm battery supply from fuseblock- connects to blue connector 20 and 57- orange
4. Electric fan 1 control from fuseblock- add a pin in blue connector pin 42
5. Electric fan control 2- add pin to red connector pin 33- originally for the hvac recirculation door
6. Fuel pump wire from fuse block- connects to 12v feed to fuel pump pnk/black on fox harness.
I disconnected the pnk/black wire under the drivers seat and made connection.
7.Crank signal from fuse block- will be wire through the clutch interlock switch on fox body harness under the dash. Its kind of a tight fit. Will be connected to red/ light blue on the clutch switch plug. Plug is located towards the top of the clutch pedal. If wired to the single output red / lt blue wire with an auto it can act as a theft deterrent. Kinda like a auto theft system. Another idea would be to wire the cranking signal wire to the brake switch that way you have to have the brake pedal depressed in order to start the vehicle. Im pretty sure it would work just like the clutch pedal. That’s for those that have 5 spd pedal assembly with an auto trans.
8. Ignition signal TO fuse block- power received directly from ignition switch. Wires must be hot in run and start. I wired mine from the ignition switch to the white and pink wire than acts as the power wire for the neutral safety switch/ clutch interlock switch.
That’s all that I have for the fuse block to the computer wiring
I am using the stock mustang gauges also. I have rethreaded the stock mustang temp sender down to the gm threads, m12 by 1.75 if I recall correctly, and installed it into the passenger side head at the back for the stock temp gauge. This means you will have the ford temp sender and the gm sender. Gm sender needed for engine operation and fan control. Ford sender for the gauge. If you still have the ford injector harness just remove the temp sender wire and the oil pressure sender wire. The temperature feed wire will connect to left instrument cluster connector at pin 3 red and white wire. The oil sender wire will connect to the right instrument cluster connector at pin 8 white and red wire. The only other wire that needs to be connected is from the computer pin 10 from the red connector. It will also be run up to the instrument cluster and connected to the left instrument cluster connector at pin 11 tan and yellow wire.

Other wires to connect are to the vehicle speed output signal wire from the red connector pin 50. That will go to your speed sensor. OBD2 port wire pin 58 on blue connector goes to input on obd2 port.


That’s as far as I have gotten so far. I will add more as I go. Again I am using a 2001 gm truck engine harness and a BPautomotive fuse block along with stock 90 model under dash wiring harness. The instrument cluster wires may be different colors for the 87-89 cars as the clusters are different and wiring also.


www.veryuseful.com/mustang/tech/engine/
www.lt1swap.com/99-02_vortec_pcm.htm

Sarg

iTrader: (6)

Subscribed for future reference! Thanks for the guide!

Sarg

iTrader: (6)

When you say ignition supply and battery supply, I am assuming that to mean that the ignition supply comes into the block from the ignition switch and is only on in the start and run key position while the battery supply is hot all the time? Also, any clue where TCC brake switch pin B33 might go to?

Or are these coming FROM the pcm going to something. A bit confused about this point.

I have three pink wires in my harness that I can not trace back to the ECU. They are on the body side of the wiring, but dissapear somewhere up into a cluster of wires leading to the engine compartment. Maybe these go to a power source?

I have one hot pink wire that is connected to pin B19 which is PCM ignition supply What does this connect to? Does it go TO an ignition 12v source?

I have two orange wires that lead to B57 and B20 which are labled in the above pin out as PCM battery supply. What do these connect to? To a constant 12V?

psiconversion

iTrader: (5)

If it helps, we are starting to list some of the schematics for various LSX Conversion platforms on our website (Mustangs, C/K Trucks, S-10s, LT1 Platforms, etc). www.psiconversion.com/tech_articles.html

It is going to include a section for gage clusters, ac, four wheel drive and various connector views. Right now I have some mustang gage schematics on the site if that would help. If you need other stuff, PM me and let me know SPECIFICALLY what you want. I will do my best to get it up in a timely manner. FYI, the intent is not to duplicate engine schematics, etc, that are listed on other websites. It is to provide more FREE information to ease board members and customers swaps.

Jon
PSI

Sarg

iTrader: (6)

Thanks Jon. Next one I do will definitely get a PSI harness!

club_xcursion

iTrader: (6)

good info. def going to subscribe for future use. i still havent decided if im going to try a re-wire of just buy a new one.

tschellinger2

How exactly did u wire the starter/battery/ignition on your ls foxbody swap? Did u utilize the factory ford starter solenoid?

zipster

iTrader: (5)

When I did mine I removed the Ford starter solenoid and used the trigger wire to activate the GM starter. Simple and alot cleaner.

chevydillan

iTrader: (2)

Sub'd

tschellinger2

Any chance you could elaborate on how u ran the wiring w/o using the foxbody starter solenoid? Did you have to do anything with the NSS or CIS? I tried making a post to look for answers, but nobody seems to be biting.