Speartech Harness question
Speartech Harness question Well with the weather getting warmer I am finally getting around to wiring the AC system in my hybrid. I had Speartech modify the harness and there is a single wire on the interior that is marked AC. My question is where do I wire that to? Is it just looking for 12v to tell the PCM to start the compressor? I am assuming I need to wire it to the ac switch on the dash but where to get it enabled for defrost etc?
John are you out there?
Thanks
Mike
John are you out there?
Thanks
Mike
Staging Lane
Joined: Mar 2003
Posts: 50
Likes: 0
From: Portsmouth, Virginia
Assuming that Speartech follows GM thinking, it goes to your AC request switch and is fed by a fused 12v source. This 12v signal tells the PCM to turn on the AC and to control the idle to compensate for the additional drag. The PCM grounds the AC relay which sends 12v to the AC clutch (assuming that the Hi/Lo pressure switch allows the signal to pass). Be sure you use the pressure switch (located in the high pressure line) so you don't toast your compressor or blow a line due to freon charge problems.
I am using all the other wiring for it I just was wondering where to pick up the AC request and if that was where I needed to terminate for sure. I dont want to send 12vdc to something that is looking for a contact closure.
Joined: Nov 2001
Posts: 1,707
Likes: 33
From: Anderson, Indiana
The green wire should go to the low pressure cycling switch on your vehicle. When you turn on the A/C and the pressure is correct, 12 volts is applied to the green wire which goes straight to the A/C compressor clutch.
__________________
91 Z28 LS2 408CI, LS9 Supercharger, LPE GT7 cam, Yank3000, 3450 raceweight.
Latest numbers: 9.71 ET, 141.42 MPH, 1.40 60' , 610 RWHP Mustang Dyno
www.speartech.com
91 Z28 LS2 408CI, LS9 Supercharger, LPE GT7 cam, Yank3000, 3450 raceweight.
Latest numbers: 9.71 ET, 141.42 MPH, 1.40 60' , 610 RWHP Mustang Dyno
www.speartech.com
The low pressure cycling switch??? Is that run through the **** on the dash? I am assuming the pressure switch is located in the dash and run to the control **** on the dash.
Now I am more confused.
Now I am more confused.
Joined: Nov 2001
Posts: 1,707
Likes: 33
From: Anderson, Indiana
I have no clue how the RX7 controls A/C, but in a typical GM A/C system when you turn on the A/C from the dash, that sends 12 volts out to the low pressure switch under the hood. If there is sufficienct freon in the system, the low pressure switch contacts are closed, and allows the 12 volts to go to the A/C compressor clutch.
If you don't have a pressure switch then the output wire of your dash switch should just tie directly to the green wire. Then when you turn on the A/C the compressor starts running.
If you don't have a pressure switch then the output wire of your dash switch should just tie directly to the green wire. Then when you turn on the A/C the compressor starts running.
__________________
91 Z28 LS2 408CI, LS9 Supercharger, LPE GT7 cam, Yank3000, 3450 raceweight.
Latest numbers: 9.71 ET, 141.42 MPH, 1.40 60' , 610 RWHP Mustang Dyno
www.speartech.com
91 Z28 LS2 408CI, LS9 Supercharger, LPE GT7 cam, Yank3000, 3450 raceweight.
Latest numbers: 9.71 ET, 141.42 MPH, 1.40 60' , 610 RWHP Mustang Dyno
www.speartech.com
