850 Climate Control

vibbase · Post by **vibbase** » 01 Apr 2006, 18:06

Hi everyone. I just bought a '96 850GLT Wagon with 175k on it. Beautiful car. It's replacing my '90 740GL Wagon that needs more money than I'm willing to spend. So, I'll spend it on the new one.

Anyway, my question is regarding the climate control. It operates erratically and is sensitive to the position of the panel dimmer switch. I suspect a short with the backlight of the control panel since there is no lighting on it at anytime. Someone at a local used Volvo shop told me I have to replace this entire module. Any tips? I would like to be able to remove it and have a look if that's possible. I'm very comfortable with most jobs. (I replaced the evaporator in my 740 for example) Thanks.

White850Turbo · Post by **White850Turbo** » 02 Apr 2006, 06:41

It's easy to pull out and take a look and prod around w/ a multimeter if you want. Just pull the radio out and push the climate control panel out from the back.

vibbase · Post by **vibbase** » 02 Apr 2006, 08:53

Thanks Sean, I'll give it try this afternoon.

vibbase · Post by **vibbase** » 02 Apr 2006, 16:09

OK, I got the unit out. There was one bulb burnt but I can't get a new one today. I have my doubts about one bulb being the problem. I'm thinking I'll get a replacement unit and give it a try.

White850Turbo · Post by **White850Turbo** » 03 Apr 2006, 06:09

Don't get the bulb from the dealer unless you like the idea of paying $8 for it. I'm not joking

.

As for a replacement unit, sounds like a plan. Check out www.car-part.com to search for used ones.

vibbase · Post by **vibbase** » 03 Apr 2006, 14:15

Thanks again Sean. I found several sources in my area. They run around a hundred bucks. I guess if I drove to the yard and got it I could install it right away to test the function. Will earlier year controls work in my 96 or does it have to be year specific?

White850Turbo · Post by **White850Turbo** » 04 Apr 2006, 06:20

vibbase wrote:Thanks again Sean. I found several sources in my area. They run around a hundred bucks. I guess if I drove to the yard and got it I could install it right away to test the function. Will earlier year controls work in my 96 or does it have to be year specific?

As long as it has the unit is the same, there should be no problems.... model year shouldn't matter, but I'd go for '94 or later b/c there were a lot of things that were different in '93.

vibbase · Post by **vibbase** » 08 Apr 2006, 15:58

I've been playing around with different ideas on this auto climate control. I found one bulb burnt out. So, I removed it. No difference. The climate control works fine (except AC doesn't come on) when I dim the panel lights. If I have the panel lights on full, the climate control runs at high speed and nothing changes when the knobs are turned. So, I dim the lights and everything goes to the right settings. Very strange. I tried jumping the pressure sensor on the AC line but the compressor didn't kick in either. All the fuses are intact. I'm picking up a used climate control module (dash unit) next week and see what happens. I bought the car this way because other than this, it's in very good condition. I hope I didn't bite off more than I can chew.

vibbase · Post by **vibbase** » 13 Apr 2006, 13:46

Ok, I tried 3 different used units. 2 from a '96 and one from a '94. One of the '96 units did nothing at all. The other 2 did the same thing as my current module. So, am I looking at a trip to the dealer for diagnostics?