Can a 2002 truck PCM and harness support hi and low speed electric fans?
#1
Can a 2002 truck PCM and harness support hi and low speed electric fans?
I was looking at some schematics for a 2002 truck, and noticed that there were no provisions for electric fans.
Can the 2002 and older truck PCM + harness be setup to run hi speed and low speed fans? Will the fans have full functionality, such as turning on the A/C, turning off on highway, etc?
Are there any disadvantages to running the red-blue truck harnesses (? to 2004) over the blue-green truck harnesses? (05-06 I think)
Can the 2002 and older truck PCM + harness be setup to run hi speed and low speed fans? Will the fans have full functionality, such as turning on the A/C, turning off on highway, etc?
Are there any disadvantages to running the red-blue truck harnesses (? to 2004) over the blue-green truck harnesses? (05-06 I think)
#2
On The Tree
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Yes you can.
Pin 42 - empty - Fan 1 Control - This will be empty on 99-2002 harnesses. A pin can be added for electric fan control. Programming will enable the fan control. PCM supplies a GROUND to turn on a relay. If you have two fans, keep reading, pin for fan 2 will be on the RED connector C2. You must wire your fans through a relay.
Pin 33 - Dk Green - Fan 2 Control - some 99-02 harnesses will have a pin here, this was used for the HVAC Recirculation Door control. The PCM would control the A/C recirculation to help cool the a/c system if it got too hot. In an engine swap, programming can be changed to let this control a second cooling fan. Again, PCM supplies a GROUND to run on a relay. You must wire your fans through a relay.
Got this info from www.lt1swap.com.
Tim.
Pin 42 - empty - Fan 1 Control - This will be empty on 99-2002 harnesses. A pin can be added for electric fan control. Programming will enable the fan control. PCM supplies a GROUND to turn on a relay. If you have two fans, keep reading, pin for fan 2 will be on the RED connector C2. You must wire your fans through a relay.
Pin 33 - Dk Green - Fan 2 Control - some 99-02 harnesses will have a pin here, this was used for the HVAC Recirculation Door control. The PCM would control the A/C recirculation to help cool the a/c system if it got too hot. In an engine swap, programming can be changed to let this control a second cooling fan. Again, PCM supplies a GROUND to run on a relay. You must wire your fans through a relay.
Got this info from www.lt1swap.com.
Tim.
#3
Has anyone here actually done it successfully?
It seems like my options are 1) buy an 2005-2006 harness and have someone program in the single-wire A/C request, or 2) buy a 2002 harness and have someone program in the electric fans.
Is there any year/vehicle truck that has both single-wire A/C request (not serial-bus) and electric fans?
Also, any benefits of red-green vs. blue-green harness and PCM?
It seems like my options are 1) buy an 2005-2006 harness and have someone program in the single-wire A/C request, or 2) buy a 2002 harness and have someone program in the electric fans.
Is there any year/vehicle truck that has both single-wire A/C request (not serial-bus) and electric fans?
Also, any benefits of red-green vs. blue-green harness and PCM?
#5
I am pretty sure they did - I feel like I've seen them in trucks at the junkyard. On the one I remember seeing, the cooling fan relays were housed in a small fuse box separate from the main fuse box.
Plus, I just dug up a cooling fan diagram from ARRC for a 2006 Silverado 1500 4.8L.
Plus, I just dug up a cooling fan diagram from ARRC for a 2006 Silverado 1500 4.8L.
#7
11 Second Club
iTrader: (5)
Yes it can be done, have done it many times on many swaps.
Pin the ECU like stated a few posts above.
Then, use your tuning software to change the pin outputs from Recirc operation to Fan operation.
I would provide screenshots in HP Tuners of this, but not at home computer at the moment.
But yes, it without a doudt can be done.
And yes, Silverado's cam with electric fans starting around 2005-6ish. My 2006 Silverado has them.
Pin the ECU like stated a few posts above.
Then, use your tuning software to change the pin outputs from Recirc operation to Fan operation.
I would provide screenshots in HP Tuners of this, but not at home computer at the moment.
But yes, it without a doudt can be done.
And yes, Silverado's cam with electric fans starting around 2005-6ish. My 2006 Silverado has them.
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#8
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Second 96GT. We tune all of our truck computers for electric fan control (unless a customer doesnt want it).
Jon
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#15
#16
sawzall wielding director
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See this thread http://www.hptuners.com/forum/showth...est-type/page2. HPT just added the A/C request feature. I haven`t tried it yet, but you should be able to reset the blue/green PCM to analog cycling and put a +12v signal to Connector C2 pin 17 Pin 43 will provide a ground output for the a/c clutch relay control and pin 55 will expect a - input from the a/c low pressure sensor. (I can`t confirm but by looking at the 2003 chevy express van diagrams it looks like the PCM expects an open circuit on pin 55 when the A/C pressure is within range and a ground when the a/c pressure drops below minimum)
#17
Efan question
Yes it can be done, have done it many times on many swaps.
Pin the ECU like stated a few posts above.
Then, use your tuning software to change the pin outputs from Recirc operation to Fan operation.
I would provide screenshots in HP Tuners of this, but not at home computer at the moment.
But yes, it without a doudt can be done.
And yes, Silverado's cam with electric fans starting around 2005-6ish. My 2006 Silverado has them.
Pin the ECU like stated a few posts above.
Then, use your tuning software to change the pin outputs from Recirc operation to Fan operation.
I would provide screenshots in HP Tuners of this, but not at home computer at the moment.
But yes, it without a doudt can be done.
And yes, Silverado's cam with electric fans starting around 2005-6ish. My 2006 Silverado has them.
#18
I'm going through this right now myself. Have an '02 Silverado with 6.0L swap, running a 411 PCM with 2001 Silverado O/S, with RED/BLUE connectors, and just did the E-fan conversion today. I got my fans from an '06 Silverado and have the factory wiring harness and fuse/relay box. Everything is wired up, but it's not working correctly. I have the GREEN fan control wire pinned to pos. 42 in the BLUE connector, and the BLUE fan control wire pinned to pos 33 in the RED connector.
Problems;
* Passenger side fan (#2?) starts running as soon as the engine starts and never shuts off
* A/C compressor turns on and runs with the fan controller in any position other than "OFF" regardless of if the A/C button is depressed or not
There was a GREEN wire already in pos 33 in the RED connector which I've learned is a A/C Recirc wire. I pulled that wire and just taped it up and put the BLUE fan control wire into that position.
My questions;
#1 Should I put the A/C Recirc wire back into position 33 and just use a relay to give a (-) signal to turn on the 2nd fan when the A/C is active?
#2 If I wire it such that the 2nd fan is on anytime the A/C is on it will basically run even if I'm doing 65 MPH down the freeway.. Is it really necessary to have the fan running even if there is enough airflow over the A/C condenser & radiator? Should I just wire in a pressure switch that will only kick the fan on at a pre-set A/C pressure? I assume that pressure will build due to heat. Adequate airflow over the condenser should keep the heat and resultant pressure below the threshold of the switch. Work?
#3 WHY is my low speed fan staying on all the time?
I'm reading all I can right now about this and there are HUNDREDS of posts scattered across the web with conflicting information. I have HP tuners and have presently copied the fan control data from a '02 Camaro F-body. I will try those settings in the morning to see if the fans work better, same, or worse.
Problems;
* Passenger side fan (#2?) starts running as soon as the engine starts and never shuts off
* A/C compressor turns on and runs with the fan controller in any position other than "OFF" regardless of if the A/C button is depressed or not
There was a GREEN wire already in pos 33 in the RED connector which I've learned is a A/C Recirc wire. I pulled that wire and just taped it up and put the BLUE fan control wire into that position.
My questions;
#1 Should I put the A/C Recirc wire back into position 33 and just use a relay to give a (-) signal to turn on the 2nd fan when the A/C is active?
#2 If I wire it such that the 2nd fan is on anytime the A/C is on it will basically run even if I'm doing 65 MPH down the freeway.. Is it really necessary to have the fan running even if there is enough airflow over the A/C condenser & radiator? Should I just wire in a pressure switch that will only kick the fan on at a pre-set A/C pressure? I assume that pressure will build due to heat. Adequate airflow over the condenser should keep the heat and resultant pressure below the threshold of the switch. Work?
#3 WHY is my low speed fan staying on all the time?
I'm reading all I can right now about this and there are HUNDREDS of posts scattered across the web with conflicting information. I have HP tuners and have presently copied the fan control data from a '02 Camaro F-body. I will try those settings in the morning to see if the fans work better, same, or worse.
#19
JPcheef-I do not believe that you can join the fan control wire, with the A/C Recirc wire like you are mentioning. They are two completely different circuits, meant to do two completely different things. Further, when you *attempt* to turn pin 33 into a fan control circuit, you have to go into the tune and change the circuit type to "fan control #2". Look here; HP Tuners>System>A/C>Hardware>Recirculation Fitted> then choose Fan #2 from the drop down menu. At that point, you are telling the software that you have now added a fan to that pin. You cannot-IMO, tie the 2 wires together.
What I'm learning so far is that even if you change the drop down to show FAN #2 it does not work. Many posts are discussing having to do a complete Over write with a different O/S just to be able to control 2 electric fans independently with the 411 PCM. I'm still looking for a CORRECT answer as well. If I figure something/anything out, I will post back here with the fix.
What I'm learning so far is that even if you change the drop down to show FAN #2 it does not work. Many posts are discussing having to do a complete Over write with a different O/S just to be able to control 2 electric fans independently with the 411 PCM. I'm still looking for a CORRECT answer as well. If I figure something/anything out, I will post back here with the fix.
#20
hello, can you provide me witn a screenshot of the tune settings? i have my ecu hptuned for the fans to turn but they only tunr an a low, the high speed does not work. any ideas?