AC not staying on

jpbriceno · Post by **jpbriceno** » 22 Jun 2005, 12:57

I am going to do my best in describing what is happening with my 1996 850 GLT's AC unit.

A few months back I noticed that my AC was not cooling as it should and has in the past. Whenever I would run the AC it would cool just as well as it ever has but random times would pass and I would have to turn the AC off then click it back on for it to turn back on and cool. The AC system is fully charged, it CAN cool (not just cool but it can chill kegs of beer in a matter of moments) yet it just won't stay on. I hear the AC's clutch engaging and disengaging about every 3-4 seconds.

I was told by some "friends" at the dealer to check a connection at the firewall, another near the passenger's side headlight, and one behind the AC compressor itself. Now, I have checked the connection at the firewall with a test light and got a glow so that is all good. I can't even find this other connection that they are talking about near the passenger's side headlight, and I fail to see how I can check that connection behind the compressor without having to do major work to get my hands in to check it.

Am I even on the right track in your opinions? I "feel" that maybe a connection is faulty somewhere, or a relay went bad or is dying. If and when the AC is on for more than a few moments it is spewing forth ridiculously cold air.

Any help and insight would be GREATLY appreciated.

P.S. - anyone know of a website that has Volvo wiiring diagrams/schematics online to view? I'll pay if necessary.

~ Patrick

Tsquared · Post by **Tsquared** » 23 Jun 2005, 04:35

I have had this happen on 2 different occasions to my 96. The first was a bad switch in the dash - $100 part fixed it. The second was a return hose that would colapse under the high pressure, it only did it when the outside temps were 95+.

The AC is one area I rely on my mechanic to fix. The tools necessary for a good diagnostic is a bit on the expensive side. I will dig into the engine and electronics without hesitation but the AC is one of the areas that I leave to the guys that work on Volvo's every day.

Good Luck,

T

JAZ · Post by **JAZ** » 25 Jun 2005, 16:20

What was the fix for the return hose. Did they have to change the hose?

My car does exactly the same thing and the system has been vacumed and refilled 2 days ago by a Volvo mechanic. It seems that it only does it over 90 degees because i took a ride for 1 hours in the morning and it was fine and in the hot afternoon it would shutdown every 5 minutes. I turn off the switch 10 minutes and it'll go but only for another 5 minutes.
Please. Any help is greatly appreciated as i have been on this ac thing for a long while now.

Tsquared · Post by **Tsquared** » 26 Jun 2005, 07:05

Replaced the hoze and full service of the system (new freon and oil). This was 2 years ago and it is still running strong.

JAZ · Post by **JAZ** » 26 Jun 2005, 08:13

What about the Ac switch. How did you find out it was faulty? I switch my ac off and the air still comes in cold. Could that be the switch or should i go for the hose?

JAZ · Post by **JAZ** » 26 Jun 2005, 08:19

Sorry, forgot to ask. Is the hose a metal one or should i be looking for a rubber hose. I don't think AC systems use rubber hoses right? and do you know where the hose is located?

Guest · Post by **Guest** » 27 Jun 2005, 08:05

Don't remember what type of hose it was, sorry.

The AC switch would initially buzz and I would loose the AC. I could toggle it on and off and it would start working. I thought I could take it apart and clean the contacts but it was spring loaded and blew apart when I tried to open it. It did have burnt contacts.

Guest · Post by **Guest** » 27 Jun 2005, 08:16

Then it has to be a hose. Just had the system vacuumed and recharged. dammit . going to have to do it all over again.

JAZ · Post by **JAZ** » 27 Jun 2005, 09:57

When you say the hose would collapse, what do you mean? What is clogged or what?