A/C Compressor Short

[06grandprix93]

So, my A/C hasn't been blowing cold air for quite some time now. I realized that the compressor clutch isn't engaging at all, and that the compressor clutch fuse is blown. I've already traced the harness coming from the compressor all the way to the back of the engine bay and didn't notice any chafed wires or anything else unusual. Where should I begin looking for a short? I don't plan to take it to a shop because I can live without A/C and I'm cheap lol.
Thanks

[Scottydoggs]

if your out of refrigerant the a/c clutch wont turn on, best bet is to go to shop and have it tested out there, unless you have a a/c vac and gauges for a/c.

or you could do what most of the time costs more, and buy a can of the leak detector refrigerant, fill the system and look for the leak via the dye, and fix what ever is leaking.

on a side note letting used refrigerant into the air is BAD, and you dont want to do that, the shop can vac out the old stuff and reuse its so its like paying the same because you keep having to buy new refrigerant when you let it go in the air, or pay the shop, either way it will wind up being close to the same price.

[06grandprix93]

I forgot to mention that I already bought dye and found no leaks in the system. Even if my refrigerant is low, that doesn't explain why the fuse keeps blowing, does it?

[gtp leslie]

i have the same problem i replaced the orifice tube and accumulator last night and had it vaccumed and recharged today but the compressor would kick on. i cheched the fuse and it was blone. i put a new one in and it blew right when i turnd it on. it might be that the cluch is fried and you have to replace the whole compressor.

a way to check and see if its blowing before it even gets to the compressor is grab a jump box and hook up wires the the pos and neg clips. unplug the wires to the compressor and put the wires from your jump box to the two posts on the compressor. if the cluch is engaging. if it is you know it electical. if it doesnt than its the compessor. not the safest way but its a way to find out what side the problem is on. i will be doing it soon to see what the problem is with mine.

keep me posted i would like to know whats up with mine too

[06grandprix93]

Okay, that makes sense, but I'm not sure that I'm comfortable using a jump box on my compressor. Can anyone else chime in and give me some re-assurance?
Thanks

[gtp leslie]

i did it to it before and didnt have any problems. the low pressure switch wouldnt let it kick on. so before i did any work to it i wanted to make sure the compressor was still good and i jumped it. the thing kicked right on and worked so shut off the jump box its all 12volt so it cant hurt it

[gtp leslie]

after talking about it i decided to go give it a shot. jumped it with two wires and my jump box and it kicked right on. i went in the car and have ice cold air coming out of the vents. so i know the compressor is still good. i just have a short in the wire.

im thinking it would be less of a pain to just find out where the two wires start at and just run new ones to the compressor than trying to track the wire and find a short it in. the car is lowerd and i dont have a jack so i cant get under it. does anyone have an idea of where the two wires from the compressor would start at??

[06grandprix93]

Thanks for all of your help gtpleslie. Instead of attempting to jump the compressor, I simply unplugged the harness and tested for current with my multimeter. There was no current, so the issue is electrical. The a/c clutch fuse is blown, so that could be why I'm not getting any current to the compressor. How can I fix the blown fuse to be able to test for current to the compressor accurately? To narrow the issue further, I checked for current on the pressure switch. It is a three pin connector (one signal wire, one ground, one power), and my multimeter read 5v, which is correct. This tells me that low refrigerant is not the issue. I found a couple youtube a/c troubleshooting videos with a lot of excellent tips. Here are the links.

Part 1 - YouTube - ‪A/C Troubleshooting(part 1)of 2‬‏

Part 2 - YouTube - ‪A/C Troubleshooting(part 2)of 2‬‏

[06grandprix93]

There is also an A/C clutch diode, and if I'm not mistaken, this is there to prevent high spikes in voltage that would otherwise blow the A/C clutch fuse. Well, since my A/C clutch fuse is blown, could it be because the diode is not functioning properly????????????????????
Update: Since a diode is simply a complete circuit, I removed the diode and tested it. I set my multimeter to diode testing and tried the leads on both of the diode's prongs. I got a reading of 001 ohms both ways, so I believe that tells me that there is a short in the diode. I would like to try and replace it, but have no clue where to buy an a/c clutch replacement diode? Does anyone know?

[06grandprix93]

Okay, so I removed the a/c clutch diode, turned on the a/c, and holy santa claus ****, the compressor kicked on and I got cold air. I couldn't find a replacement diode anywhere except the dealer, who had to order one in.

[gtp leslie]

so without repacing the diode it still worked?? did you just pull it out and put a new fuse in it?? i traced all the wires down to my cluch and couldnt find any problems eather so im thinking that might be whats wrong with mine????

[06grandprix93]

Yeah, to test if the diode was the issue and causing the fuse to blow, I just removed the diode and the compressor came on. Now, I'm just waiting for a new diode to arrive at the dealership.

[06grandprix93]

I replaced the diode, and the fuse blew again. I'm just going to leave the diode out unless someone tells me that is a bad idea.

[gtp leslie]

whatever is wrong with your car is the same problem im having. i have the diode out now and its working, but its not good to leave it like that it protects the compessor and other electical parts. they put it in for a reason so it is ment to be there. if you leave it out you could have a dead compessor in a week, or a dead car if it shorts and cooks the computer or a wire in the dash. you might be safe for a few times on the really hot days but i wouldnt run it that long without it. this week im going to rewire the compressor in hopes that maybe its just a bad wire and see if that fixes it. but keeping it out isnt the best idea.