Hello All,

I have a 1996 850 GLT wagon, non-turbo, with a 5 speed manual which I have owned since new. It has the dual climate control feature. It presently has 282,000 miles on it. Recently, while the a/c was on, the blower began to working intermittently. When the blower stops working, it doesn't matter if you switch the a/c from the "aut" to the "manual" setting, the blower will not work. I noticed however, if I keep switching the setting from "aut" to "manual" and back, after a while the blower will begin to work again in either mode. I can't say for sure if the "switching" of the blower setting is what "restored" it. When the blower begins to work again, I noticed no change to the usual sound that it generates. I checked the fuses and they are fine. This is the original climate control unit that came with the car. This problem occurs imtermittently but is the first time I have ever experienced it on this car.

Does anyone have any idea what could be causing the blower to cut in and out like it does? Thanks in advance to all who respond, I appreciate your help very much.

Hugh

I believe the name of the contact cleaner is CRC and can be found in almost any auto parts store.
RK

RK,

I want to thank you and all the others who responded. I purchased the electric contact cleaner and sprayed it on the switch/button that activates the blower. So far it seems to have worked in terms of preventing the intermittent operation of the blower. I'm keeping my fingers crossed. My wife drives this car, so I have to make it a point to ask her each day if the blower is acting up again. So far, the answer is "no". But it will be probably another two weeks before I know for sure.

If this contact cleaner is successful all of you have saved me a boat load of money. I priced the parts for the resistor and the blower and neither was cheap.

Thanks!

Hugh

RK,

I must lead a charmed life. I just came back from my local NAPA store and that is exactly the product they sold me a can of: QD Electronic Cleaner by CRC. Thank you for getting back to me. I'm keeping my fingers crossed this solves the problem.

Hugh

The brushes are probably loosing contact with the armature. As they wear the brush wire looses slack and stops the brush from moving. The motors are very easy to take apart. If you're handy with a soldering iron you can uncrimp the brush wire and slip it a little in the lug on the mounting board in the motor. That should give you a few more months of operation. To take the motor apart simply pry out the connector adapter and remove the single screw on the end of the housing. The motor and fan should then pull out easily.

Fixit2002,

Thanks for the help. I appreciate it.

Hugh

A friend of mine had the same problem, I sprayed some contact cleaner into the slot for adjusting the fan speed, moved the switch back and forth a few times and all was well again. Over time dust and dirt tent to get into these areas and clog things up.
Good luck, RK 94-850T, 98 V70XC

RKMACMAN,

Thanks for your reply. What was the name of the contact cleaner and where can I purchase it?

Hugh

Time to do some reading, I just did a search on blower:

http://www.brickboard.com/AWD/volvo/1285290/850/blower_power_stage_fix_pics.html

There are 2 different power stage modules, one for MCC and one for ECC. ECC has variable fan speeds, the MCC has 0-4 speeds.

Klaus
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The more I learn, the more I forget. So why learn?

Klaus,

Thanks! I did a thread search, but did not obtain the detail responses you listed. I guess I used the wrong search words. I assume that MCC and ECC mean
"maual climate control" and "electronic climate control" respectively?

I'm hoping by applying some contact cleaner to the slot that control the blower will resolve the problem. I get the impression the blower and resistor are big ticket items if purchased new. Any idea how much they go for at your local Volvo dealer?

Hugh

The MCC resistor is under $100 and ECC resistor is over $100 at FCP Groton.

Klaus
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The more I learn, the more I forget. So why learn?

Klaus,

I'm always impressed by your knowledge of Volvos. One of the other respondents suggested a contact cleaner to apply to the control button that switches between the "AUT" and "Manual" settings for the blower.

Other than blowing out the dashboard switch with compressed air to remove built up dust, do you know of any contact cleaner that can be applied to inprove the electrical contact. The possibility of "blowing this problem" away without the necessity and expense of purchasing replacement parts appeals to me immensely. Thanks!

Hugh

At your local auto parts store. Electrical contact cleaner can safely be sprayed into the switch to clean off dust and grime. Just don't soak it or have the key in the ignition until it dries - 30 seconds or so.

If you had a multimeter, I would suggest checking the wiring at the rehostat and at the blower for 12V. But the speed needs to be at max without the blower working.

Klaus
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The more I learn, the more I forget. So why learn?

Klaus,

Was I right about what "MCC" and "ECC" stood for? How much does the blower motor go for itself?

Hugh

M = manual, E = electronic. A blower motor varies depending on assembly, $150+

Klaus
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The more I learn, the more I forget. So why learn?

Klaus,

Thank you for your two replies. I'm armed with knowledge now. I know I might be unrealistic, but I'm hoping by using that contact cleaner I can solve this problem. Klaus, how did you come be be so knowledgable about Volvos, in particular the 850-S70 and V70 models?

Hugh

It was easy. Four years of reading every post on the AWD/front wheel drive section. Plus having an 850 and V70 helped.

Klaus
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The more I learn, the more I forget. So why learn?