stand alone harness and fan help

[CCT]

I have a GM stand alone harness with dual fans. I also have a GEN 4 Vintage Air. My question is what is the easiest was to wire the fans. The engine harness has a wire coming out for the fans. The fans need to be on when the AC is what I think. What's the way was to make the fans work with both?

[andrewb70]

I have a GM stand alone harness with dual fans. I also have a GEN 4 Vintage Air. My question is what is the easiest was to wire the fans. The engine harness has a wire coming out for the fans. The fans need to be on when the AC is what I think. What's the way was to make the fans work with both?

Does your harness provide a ground of a positive signal to trigger the fans?

Andrew

[badazz81z28]

LS im thinking? The ECM will have two activation (ground) wires. Which will be the ground for the relays. I would think the easiest way is to create another activating ground wire that triggered by the AC on switch. Basically two grounds spliced for the same relay which one goes to the ECM and the other to the AC switch.

[DIY TA]

Just wondering but ecu are you using? The BEST way to get your fans to command on when the ac compressor starts is to use a trinary pressure switch. You car probably uses a binary switch. A trinary switch has a ground side to it that grounds when the ac commands on. If you run a wire from that ground and wire it into your ecm ground rely wire (fan) it will override the computer the turn the fans on. Hope that helps.

[BuzzKillian]

LS im thinking? The ECM will have two activation (ground) wires. Which will be the ground for the relays. I would think the easiest way is to create another activating ground wire that triggered by the AC on switch. Basically two grounds spliced for the same relay which one goes to the ECM and the other to the AC switch.

I tried this and it kept throwing an error code. If you activate the relay before the engine heats up, the computer reads the relay as faulty. I ended up using 3 relays. 1 for low activated by a trinary switch on the AC, 1 for low activated by the ECM, and 1 for high fan activated by ECM.

[CCT]

Thanks for all the replys. My computer came with the GM controller kit. I don't think it can control the fan for the AC. All this stuff is new to me. I thought about heating up the same fan relay that the computer uses with the signal from the AC. I wasn't sure if that would hurt my computer with it heating it up back to it. I guess according to BuzzKillian it may not work. I also thought about putting a diode in the line from computer to the relay. I guess I need to try to get some more info.

[andrewb70]

Thanks for all the replys. My computer came with the GM controller kit. I don't think it can control the fan for the AC. All this stuff is new to me. I thought about heating up the same fan relay that the computer uses with the signal from the AC. I wasn't sure if that would hurt my computer with it heating it up back to it. I guess according to BuzzKillian it may not work. I also thought about putting a diode in the line from computer to the relay. I guess I need to try to get some more info.

This link might help. The main topic is not what you're asking about, but there are a lot of posts how to handle the AC request. I am assuming that your harness kit uses the E67 ECU, right?

http://www.lateral-g.net/forums/showthread.php4?t=40215

Andrew

[CCT]

Andrew it a E67 ECU. Thanks for the link.

[eroc022]

I've been researching this, and was wondering, could I just run a separate fan on the a/c condenser hooked up to a trinary switch? I don't want to go through the hassle of splicing in the PWM module and tracking down excess parts.

[chpr1972]

Stupid question, have you called Vintage Air?

[rickpaw]

I've been researching this, and was wondering, could I just run a separate fan on the a/c condenser hooked up to a trinary switch? I don't want to go through the hassle of splicing in the PWM module and tracking down excess parts.

Short answer is yes. It's actually spelled out in VA instructions, on the wiring diagram.

Or, you can use the compressor trigger wire (12+) as a trigger for the fan relay, so the fan comes on every time you turn on the AC.