Removed ECM: AC/Fan wiring
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Joined: Feb 2014
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From: Pennsylvania
Car: 1986 Camaro Z28
Engine: 283 V8 NA
Transmission: TH350
Removed ECM: AC/Fan wiring
So I've trolled around the forums as a guest for years gathering helpful information, but I finally joined as I'm a little stumped. After searching around the threads for a while I just never found anything that satisfied me. I'm sure you guys can help me out though.
I have an '86 Camaro that originally had a the V6 TBI. I've since pulled the motor and swapped it for a 283 V8 (old racing motor I had laying around from years back.) I had no need for the ECM to remain so pulled it as well. I have pretty much everything figured out, but I'm struggling to comprehend some of the final wiring necessary for the fan and A/C circuits.
First the fan circuit as it's the easiest. I already handled rewiring the fan so it operates properly in certain temperature ranges. I'm unsure what to do with the fan pressure switch. My wiring schematic shows the black going to ground and the dark blue to the ECM. Is this a normally open circuit, and when closed signaled the ECM to trigger the fan ground circuit? If so, I'd just splice the dark blue wire into the engine temperature line (dark green/white) so the fan pressure switch can activate the fan as well. I just need to know how the ECM originally handled the circuit and whether that is a "proper" way to do it.
My second issue is the A/C Wiring. Coming out of the compressor control relay is a black/pink, dark green/white, and light blue; of which the latter two run to the ECM, while the former runs to the gauge cluster albeit alongside the ECM harness. Similar to the wiring of the fan switch, I'm unsure which of the wires are necessary to reuse. Based on my schematics, it appears I just need to wire the black/pink to any Hot-in-Run wire to power the relay. and can I just cut the other 2 wires off the relay and be done with it? I'm concerned about having all the proper safeties to keep the A/C system from over-pressurizing, and making sure the fan runs as needed.
Thanks for all your input in advance!
I have an '86 Camaro that originally had a the V6 TBI. I've since pulled the motor and swapped it for a 283 V8 (old racing motor I had laying around from years back.) I had no need for the ECM to remain so pulled it as well. I have pretty much everything figured out, but I'm struggling to comprehend some of the final wiring necessary for the fan and A/C circuits.
First the fan circuit as it's the easiest. I already handled rewiring the fan so it operates properly in certain temperature ranges. I'm unsure what to do with the fan pressure switch. My wiring schematic shows the black going to ground and the dark blue to the ECM. Is this a normally open circuit, and when closed signaled the ECM to trigger the fan ground circuit? If so, I'd just splice the dark blue wire into the engine temperature line (dark green/white) so the fan pressure switch can activate the fan as well. I just need to know how the ECM originally handled the circuit and whether that is a "proper" way to do it.
My second issue is the A/C Wiring. Coming out of the compressor control relay is a black/pink, dark green/white, and light blue; of which the latter two run to the ECM, while the former runs to the gauge cluster albeit alongside the ECM harness. Similar to the wiring of the fan switch, I'm unsure which of the wires are necessary to reuse. Based on my schematics, it appears I just need to wire the black/pink to any Hot-in-Run wire to power the relay. and can I just cut the other 2 wires off the relay and be done with it? I'm concerned about having all the proper safeties to keep the A/C system from over-pressurizing, and making sure the fan runs as needed.
Thanks for all your input in advance!
Re: Removed ECM: AC/Fan wiring
Read over the total fan control thread. Use a thermal switch to activate the fan(s). No need for an override when using Ac
Check your wiring schematics for your year/engine and identify the output wire from the relay to compressor. Cut it free and connect it to the Ac request (lt blu) wire from the hvac connector. Now you head unit will energize the compressor. TBI cars did it this way, so it won't hurt anything
Check your wiring schematics for your year/engine and identify the output wire from the relay to compressor. Cut it free and connect it to the Ac request (lt blu) wire from the hvac connector. Now you head unit will energize the compressor. TBI cars did it this way, so it won't hurt anything
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