6.0L LQ4 with Denso A/C Compressor Question
6.0L LQ4 with Denso A/C Compressor Question Hello,
I am installing a Classic Auto Air unit into my '69 Chevy Truck with a 6.0L LQ4 Chevy. I am using a Speartech Harness and I have a question on how the compressor should be wired.
I have used the search feature and read through the FAQ's but haven't found what I am looking for.
On the Denso Compressor there are 2 - 2 pin connectors. The speartech harness connects to the connector with the Green/White wire and Black wire. On the back of the compressor is a purple connector with 2 very small pins.
On the receiver is a High/Low switch with 2 white wires. one wire is supposed to go to the compressor and one wire is supposed to go to the thermostat.
There is also a Dark Green wire with the Speartech harness that is labeled A/C Compressor which is supposed to be connected to the controller. I think I can figure this one out.
1. With the PCM is the High / Low Switch required? If so, how do you wire it in so it is functional?
2. What is the Purple connector at the back of the comprerssor for?
Any other insights would be greatly appreciated.
Thank you for you help.
I am installing a Classic Auto Air unit into my '69 Chevy Truck with a 6.0L LQ4 Chevy. I am using a Speartech Harness and I have a question on how the compressor should be wired.
I have used the search feature and read through the FAQ's but haven't found what I am looking for.
On the Denso Compressor there are 2 - 2 pin connectors. The speartech harness connects to the connector with the Green/White wire and Black wire. On the back of the compressor is a purple connector with 2 very small pins.
On the receiver is a High/Low switch with 2 white wires. one wire is supposed to go to the compressor and one wire is supposed to go to the thermostat.
There is also a Dark Green wire with the Speartech harness that is labeled A/C Compressor which is supposed to be connected to the controller. I think I can figure this one out.
1. With the PCM is the High / Low Switch required? If so, how do you wire it in so it is functional?
2. What is the Purple connector at the back of the comprerssor for?
Any other insights would be greatly appreciated.
Thank you for you help.
The pcm has to have the low pressure cycling switch wired into the pcm before it will command compressor operation. This is the one on the dryer. The switch on the back of the compressor is the high pressure cutout switch and it to must be wired to the pcm before the can command the compressor on. This is still provided it is flashed with a truck tune and not one that bypass' these functions in the pcm. Just grab a pinout of the pcm connector and run four wires to the pcm and hook the switches up and then place the pin connectors in the correct spot on the pcm. It also must have an a/c request signal to the pcm from your vehicle.
TECH Apprentice
Joined: Aug 2005
Posts: 347
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From: Dover Arkansas
I believe you just wire the low pressure cutout switch in line with the AC on request wire from the switch. This way, if pressure is low the lp switch opens and you don't get AC on request signal to the computer.
Thank you all for the replies....
I hooked one side of the limit switch to the Speartech Green wire (Which goes to the Compressor) and the other side of the limit switch to the A/C Thermostat (On the CAA Unit). I think I was making it more complicated than it needed to be.
As far as connections to the SpearTech harness there were two to make it run (Pink (switched 12 Volt) & Orange (Constant 12 volts)) there are four additional wires, 1 to Fuel Pump, 1 to AC Compressor, and 2 for Fan Relay.
Hope this helps and thanks again to those that replied.
I hooked one side of the limit switch to the Speartech Green wire (Which goes to the Compressor) and the other side of the limit switch to the A/C Thermostat (On the CAA Unit). I think I was making it more complicated than it needed to be.
As far as connections to the SpearTech harness there were two to make it run (Pink (switched 12 Volt) & Orange (Constant 12 volts)) there are four additional wires, 1 to Fuel Pump, 1 to AC Compressor, and 2 for Fan Relay.
Hope this helps and thanks again to those that replied.
