AC question - HELP PLEASE

[Max]

You're good.

That compressor cycling in and out COLD was just proly the thermistor (thermostat) maintaining the temp at the evaporator.

If you're still nervous about the A/C...High and low gauge pressures reading will confirm.

[cubicleman]

Max...I think you are right...the problem hasn't happened to me for weeks, I just post saying that and then it happened today on my way to work. What I thought about was that the last time it happened the weather was spring time and in the 70deg range. Today was the same, so I started to think that maybe it's related to the outside temp and some sort of thermistat. I'm not sure if this is what the thermistor does, but could you point me to where it is located?

[Max]

It's part of the evaporator unit (behind the dash) but I don't think it is the problem. I mentioned it only to comment that it is probably doing it's job (cycling the compressor) as designed to keep the evaporator temp from becoming too cold and causing a freeze up situation.

The first step in diagnosis is to get those running pressures (low and high side) combined with outlet air temp, checked to determine compressor and refrigerant charge condition.

IF your charge state isn't correct, the unit can also cycle on the high / low pressure switch as well!

[netlos]

Hey guys instead of starting a new thread i decided to tag along hope nobody minds!Took a look at my A/C today the clutch engages when bypassed,loacted the 25amp fuse for the A/C(it's blown),now that i'm sure the clutch engages freely i will try out a new fuse (got to go buy some).will keep you all posted.The only reason i decided to look at it myself is cause the kids are at granmas, i'm off work today,and of course the great info on this forum!Wish me luck!

[Max]

There's ALWAYS room for one more!

And yes, good luck Net!

Hand over hand inspect that compressor wiring. It may be pinched or is chaffed causing a short to ground.

If you continue to smoke fuses, I'd suspect the relay after checking all wiring and connections.

[netlos]

Hey Max,the wiring looks good,the new fuse has not blown ,but i get no power to the compressor,is the relay the one located above the low pressure test point in front of the rad on the top left side (standing in front of the car) if not where is the relay located,my wife needs the truck tonight but i will try to finish trouble shooting the problem.Thanks again !

[Max]

I'm lookin'...

Curious, does your electric fan come on when you mash the A/C button? It should, the same time that the clutch gets voltage. (inside blower fan switched on too of course at this point).

Still lookin...

[Max]

Can you read this? It may help as we go. Note the FOUR fuses (across the top) related to the A/C system.

Right button click, save, open in your photo program and enlarge it if you need to.

[Max]

From the FSM. It didn't make the cut and paste trip all that well, but you can get the idea. Do you have a copy of the FSM? I could help guide you better.

Cool air won’t come out
(A/C compressor won’t
operative)
Magnet clutch faulty
Compressor relay faulty
Compressor thermal switch faulty
(if equipped)
Drive belt loose or broken
Compressor faulty
A/C ON permission signal in ECM
faulty
A/C controller faulty

Check magnet clutch.
Check compressor thermal switch.
Check compressor relay.
Adjust or replace drive belt.
Check compressor.
Check ON permission signal.
Check A/C controller

[Max]