flaky A/C operation

Topic: flaky A/C operation (Read 2521 times) previous topic - next topic

flaky A/C operation

August 05, 2005, 09:13:57 AM

Hey all,

Replaced everything under the hood last summer in my 88 XR7 and converted to r134a: condensor, compressor, dryer, pressure switch, all lines. The car has manual A/C and the head unit seems fine.

But recently the a/c comes on and off whenever it wants. When it does come on, its ice cold, so its not low on r134. Drove to work today, the A/C wheezed out of the dash after about 10 mins of use. Opened the hood at work and sure enough the compressor was not turning.

I tested the pressure switch on the dryer, it works fine...the problem is upstream...I hear a relay clicking (near the airbox, bolted to the fender apr0n) when I jump the pressure switch on the times when the compressor will not engage.

Does the clicking mean my relay is bad and that's all there is?

That would explain the intermittent-ness of this thing.

Thanks. :D

Re: flaky A/C operation

Reply #1 – August 05, 2005, 09:17:30 AM

If you jumped the switch and the compressor still did not come on, I would say you have a bad coil in the compressor clutch. It gets heated up and disengages the system.

Re: flaky A/C operation

Reply #2 – August 05, 2005, 09:29:10 AM

The clutch could be getting worn out too. The gap between plates gets too wide for the magnetism to work once heated up. The clutch needs to be taken off / apart and reshimmed. Momsy's Taurus just had it done.

Quick way to test... engine running, A/C on full so clutch SHOULD be engaged, tap the face of the clutch with a hammer handle, broomstick or similar, see if it engages.

Re: flaky A/C operation

Reply #3 – August 05, 2005, 09:38:06 AM

Quote

Quick way to test... engine running, A/C on full so clutch SHOULD be engaged, tap the face of the clutch with a hammer handle, broomstick or similar, see if it engages.

You beat me to it... Thats how mine was working, just a little tap and she engaged.

Re: flaky A/C operation

Reply #4 – August 05, 2005, 11:02:15 AM

The clutch is new too, along with all the other parts. It seems like what controls the clutch is not working 100%. But ya'll could be right, I'll give it a tap next time.

What about that relay on the fender? I heard its a WOT cutout relay and if that part is clicking intermittently, could it be the problem? From what I heard on another forum, I should jump the two big pr0ngs on that relay and see what happens.

Re: flaky A/C operation

Reply #5 – August 05, 2005, 11:30:26 AM

tap the wot relay too, couldn't hurt at this point..

Speaking of the WOT relay I had problems with that myself years back. My connector and the wires leading to it were so screwed up I went to the pick and pull and snipped off the relay and like 18" of the wire leading to it and spliced it onto my car. It worked fine after that.

Re: flaky A/C operation

Reply #6 – August 05, 2005, 12:13:46 PM

Short the pressure switch and see if you get 12V at the compressor clutch input. If not, your WOT relay is probably bad. This is a fairly common problem. If you get 12V, follow the above recommendations.

Re: flaky A/C operation

Reply #7 – August 05, 2005, 02:30:23 PM

Quote from: JeremyB

Short the pressure switch and see if you get 12V at the compressor clutch input. If not, your WOT relay is probably bad. This is a fairly common problem. If you get 12V, follow the above recommendations.

Sounds like my WOT relay is bad. Thanks guys. :)

Re: flaky A/C operation

Reply #8 – August 06, 2005, 02:58:41 AM

Mine had new seals and recharged. quit after 3 days. same deal

Re: flaky A/C operation

Reply #9 – August 06, 2005, 11:43:02 PM

I went through the same thing with my car. The WOT relay was bad. But for some reason my cutoff switch was bad as well.

Re: flaky A/C operation

Reply #10 – August 07, 2005, 05:22:52 PM

New relay ($12) and now all is well. I drove around for an hour with the A/C on and nothing bad happened, so I guess its all fixed. I also tested the WOT function and it seems to be fine...I could have just ran a code scanner on it, but that wouldn't be much fun as the lead foot method.

Thanks everyone!

Re: flaky A/C operation

Reply #11 – August 16, 2005, 10:52:52 PM

If I can ask, for those that have converted everything, how much will this end up costing me to convert mine?

Re: flaky A/C operation

Reply #12 – August 17, 2005, 11:47:55 AM

If you flush out the condensor/dryer/lines with brake cleaner and compressed air it is only the price of a compressor and the freon and PAG oil. $300 or so in parts.

But after hearing about products like Freeze 12 that works in R-12 systems, r134a isn't worth it. The R-12 is waaaay for these foxbody Fords. Too late for me, I already converted. :(

Re: flaky A/C operation

Reply #13 – August 17, 2005, 05:33:42 PM

Quote from: pro-five-oh

New relay ($12) and now all is well. I drove around for an hour with the A/C on and nothing bad happened, so I guess its all fixed. I also tested the WOT function and it seems to be fine...I could have just ran a code scanner on it, but that wouldn't be much fun as the lead foot method.

Thanks everyone!

The EEC does not monitor the WOT A/C cutout relay, so the scanner won't tell you a thing.

Re: flaky A/C operation

Reply #14 – August 17, 2005, 05:54:39 PM

I thought thats why you hit the gas (above 3000rpm or so) in the KOER test?