Electric fans on truck with ECM ??
08-10-2002 | 09:02 AM
#1
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Teching In
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From: Hameln, Germany
Electric fans on truck with ECM ?? I noticed that I can edit the electric fan parameters with LS1 Edit even on the trucks that donīt have any....question is if it would be possible to wire the fans to the ECM.
What are the pins used on the F/Y-bodys ECM that go to the fan relays?
If these pins are unused I would try to wire them on my truck to see if I can control my electric fans with them.
What are the pins used on the F/Y-bodys ECM that go to the fan relays?
If these pins are unused I would try to wire them on my truck to see if I can control my electric fans with them.
08-12-2002 | 08:04 PM
#3
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Re: Electric fans on truck with ECM ?? You know I've been wondering the same thing.
I think the computer only grounds different relays to get the fans to come on when they're supposed to.
I bet you could use some regular automotive relays and wire them to the ECM so it would turn the fans on and off.
HARLAN!!! YOOOOO HARLAN!! GET IN HERE. Here is a new product for ya. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />
John
PS - I'm emailing this link to him. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
I think the computer only grounds different relays to get the fans to come on when they're supposed to.
I bet you could use some regular automotive relays and wire them to the ECM so it would turn the fans on and off.
HARLAN!!! YOOOOO HARLAN!! GET IN HERE. Here is a new product for ya. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />
John
PS - I'm emailing this link to him. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
08-13-2002 | 07:52 AM
#4
On The Tree
Joined: May 2002
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From: Phoenix, Az
Re: Electric fans on truck with ECM ?? The 99 Camaro PCM uses pin 42 on the blue connector for fan 1 and pin 33 on the red connector for fan 2.
The Camaro is wired so when pin 42 is grounded, it turns on both fans at half speed thru relay 1. In this mode, the fans are wired in series. When called for, pin 33 is grounded and operates relays 2 and 3. This puts the fans in parellel and they run at full speed.
You can buy fans and fanstats at PEP Boys. I think the fanstat is adjustable.
The Camaro is wired so when pin 42 is grounded, it turns on both fans at half speed thru relay 1. In this mode, the fans are wired in series. When called for, pin 33 is grounded and operates relays 2 and 3. This puts the fans in parellel and they run at full speed.
You can buy fans and fanstats at PEP Boys. I think the fanstat is adjustable.
08-13-2002 | 03:58 PM
#5
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Re: Electric fans on truck with ECM ?? Ok, Harlan brought up a good point.
The temp. may be editable in LS1edit but, does the computer know if there are fans or not. If it's not somewhere in the computer that there are fans to turn on then this idea probably won't work.
Maybe someone with edit could set the fan temps low enough so they would come on before the clutch fan engages and probe the unused computer pins to see if a circuit gets grounded at the given temp. I don't know if this will work so don't blame me if you blow up your computer testing things. <img border="0" title="" alt="[Razz]" src="gr_tounge.gif" /> <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />
John
The temp. may be editable in LS1edit but, does the computer know if there are fans or not. If it's not somewhere in the computer that there are fans to turn on then this idea probably won't work.
Maybe someone with edit could set the fan temps low enough so they would come on before the clutch fan engages and probe the unused computer pins to see if a circuit gets grounded at the given temp. I don't know if this will work so don't blame me if you blow up your computer testing things. <img border="0" title="" alt="[Razz]" src="gr_tounge.gif" /> <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />
John
08-15-2002 | 05:46 PM
#6
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Teching In
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From: Hameln, Germany
Re: Electric fans on truck with ECM ?? Thatīs exactly what I was planning to do....the pin42 on the blue connector is not used but the pin 33 on the red one has the "HVAC Recirculation Door Control". I am still going to try pin 42 and see what happens.
//Lennart
//Lennart
