850 Volvo, Fan Blower Control Problem

clay roby · Post by **clay roby** » 25 Jul 2008, 08:45

My 1996 Volvo blower fan only works on the highest setting. All the fuses are good and I have replaced the resistory network in hopes of fixing this problem without luck. From physical inspection, the blower switch looks fine. It seems like it might be a ground problem but that would not explain the fact that the fan works on the highest setting. Anyone have a suggestion on what else I can check or replace?

BGPKR · Post by **BGPKR** » 25 Jul 2008, 11:50

Mine has a similar problem. The fan only works on high and when the switch is in any position. I had to pull the fuse to shut it off.

Post by **BEJinFbk** » 25 Jul 2008, 12:50

BGPKR wrote:Mine has a similar problem. The fan only works on high and when the switch is in any position. I had to pull the fuse to shut it off.

There is a relay that selects either reduced voltage from the resistors for the lower
speeds or a direct 12 volt feed for the highest fan speed setting. I would look at that.
Sounds like the contacts may be fused. Should be easy to check.

Here is a link for diagrams:

http://volvo.techno.org.pl/wiring-diagrams.html

BGPKR · Post by **BGPKR** » 25 Jul 2008, 13:02

Thanks. And where are these realys located?

Post by **Ozark Lee** » 25 Jul 2008, 14:51

Both of the problems sound a lot like relay problems. Clay, have you checked fuse number 31? If that fuse goes bad the lower fan speeds won't work but speed #4 will work.

If BGPKR has a manual climate unit then the relay is for sure bad. If it is an electronic climate unit then the power stage has shorted out.

The max fan relay is on a small shelf in front of the main air duct. It can be accessed by removing the glove box. There are two relays on a manual unit one is the A/C relay and the other is the max fan relay.

...Lee

Post by **BEJinFbk** » 25 Jul 2008, 17:13

BGPKR wrote:Thanks. And where are these realys located?

You'll find component locations in the wiring diagram manual.
It's a great book. They have Everything in there.

BGPKR · Post by **BGPKR** » 26 Jul 2008, 10:19

I called the closest dealer to me. That relay is $83.

Anyone have an online parts source that these can be found cheap?

Post by **MadeInJapan** » 26 Jul 2008, 10:32

Try eBay....yours might be different than later model 850's so shop accordingly.