CutLS

iTrader: (6)

I think I'm going to get the Vintage Air kit for my 72 Cutlass that I'm going to swap an LS1 into. Is anyone, with Vintage Air, using their PCM to help control the A/C or is the A/C system a stand alone system? I'm asking because I'm trimming my wiring harness down and am wondering if I leave in the A/C wiring in PCM connectors. Thanks.

garys 68

iTrader: (1)

I've done 2 LS swaps with aftermarket air. Just leave the ecu AC wiring out, no problems at all.

LS1MCSS

iTrader: (18)

I don't have vintage air on my car, but I wouldn't let the pcm control the air unless I was using a stock LS air conditioner compressor. I think the vintage air uses a Sanden compressor, so I would wire it the way Vintage air says to.

chuckd71

iTrader: (23)

What about wiring it so that you control the a/c but the ecu knows when it comes on so it can bump the idle? Possible?

Kingstir

I am using the pcm to control the vintage air unit in my El Camino, (LS2/4L60E). I have a Speartec harness and there is a wire to hook the compressor lead into it. There were also wires on the harness to connect to the cooling fan relays. PCM has control and will turn the fans on accordingly when high side pressures increase. It retains the factory high side pressure switch that was with the engine i bought. Normal idle drops by 200 rpm when the a/c comes on. I would be happy to answer any questions you have.

Blanchard

garys 68

iTrader: (1)

It depends on the ecu. The f body LS1 uses a 12V request sgnal but requires the f body pressure switch be grafted in. On later trucks, etc the request is a data signal.
Just leave it out. Idle is fine. I control 1 fan through the ecu, the other fan is controled by engine temp and/or a trinary switch. VA substituted the trinary for the original binary.

69 Ghost

You can wire it to the PCM. If you use the fixed compressor wire it like a truck with the binary switch. If you use the variable compressor use the pressure switch wired like a car. There is no need to spend extra $$$ for a trinary since you can control the fans with the PCM. Typical VA systems use a 12 volt request when the fan turns on and it is a high/low shutoff. From there use the factory diagram for the A/C request. The fans and everything will work properly from there.

jlcustomz

hooked vintage air stand alone to my 99' ls1 swap 4 years ago. No idle concerns & fans are stand alone also.
It's partly a matter of which compressor used & preference on which route you go.I just prefer keeping them separate.

CutLS

iTrader: (6)

I think I will try to keep the separate but I will keep the terminal wires encase I need to reinstall them. Does the VA system need to hook up to the fans at all? Does it have it's own computer to know when it should run or not run?

garys 68

iTrader: (1)

VA doesn't have a fan controller. You can substiture a trinary switch to control a fan. It's setpoints are different from the compressor so the fan only on when needed.

1texasmade

Sorry to barge in. I have the same situation. Trying to add in 03 truck 5.3 high pressure switch to control fans when the a/c is turned. I already have the fans working running parallel for high and low.can anyone lead me on the right path?

garys 68

iTrader: (1)

The easiest solution would be to splice a trinary switch into the hi or low speed speed wire to the ecu.
If you spice into the low speed, both would be on low any time the trinary switch is closed. High speed would work as it does normally.
If you splice into the hi, only one fan would run at hi speed if engine wasn't hot and the trinary switch closed.

Ogoz23

Ok just to make sure I understand this. In the trinary switch one of the wires will go connected to the pcm. That wire tells the pcm that the AC is on and it needs the fans on. At that point the computer turns on the fans . Please tell me I got this lol