Air conditioning addition confusion.

[Poweralth]

After 2.5 summers of no A/C I've finally decided to bite the bullet and install it in my truck. Problem is I can't seem to find a consensus on the stuff I need to complete it. Some posts claim I need certain plugs on my engine side wiring harness and other don't even mention it at all. I know I need the new switches to control the system on the dash but I assumed that's all I needed to tell the ECU to idle higher when the compressor is on.

 

Simply put: do I need certain connections and relays on the engine side of my truck? To make sure an A/C install would work correctly and not break anything. If I can avoid having to swap the entire wiring harness I would like that very much but if not it's just another thing to grab from the junkyard I suppose.

 

SPECS: 1987 jeep comanche base model 4.0 I6 5SPD Manual

No factory A/C but it has the brackets and mounts for compressor and I have the parts list ready otherwise.

[Gojira94]

First, welcome to the forum! Second, please post the VIN number so we can add it to the registry, one or two of our members can pull some information about its origin and a high-level list of original specs.

 

For the AC: first big item you'll need is the air box assembly inside the dash. I'm in the same boat as you, my 87 also came with no AC. The boxes are different, as there's no room/ provision for a location for the evaporator. Best advice there is to look for an AC equipped donor XJ. From that you'll need the dash controls, possibly the vacuum harness that'll be attached to the HVAC box. Also of course a new pair of low & high pressure hoses, compressor, condenser, plus more things I'm not thinking of at the moment. There should be a capped off plug on the driver's side inner fender well that could be used to essentially copy a dealer-installed AC setup and run all the digicals:

 

Others should chime in and add all I'm forgetting. And again, glad you're here.

[Poweralth]

Thank you! I forgot the Vin last night sorry! Its: 1JTMW6417HT098037

 

I saw that plug and I was hoping that's what it was for! Mine is doesn't have anything plugged into it and I have the lines and compressor and such already. I just need to go grab the control module and the air box assembly. You have been more help than you can realise thank you so much!