Hi There. The heater fan motor always works when car first starts up. It runs for awile, then will sometimes stop (does not always stop, mostly on colder days). Blower will not start up again unless car is turned off and re-started. The heater motor had made a whining sound like bad bearing or something so I thought that was the issue and replaced the heater motor/fan assembly. The problem persists. I looked around in the forum and figure it could be the resister. I don't know where that is located nor what it looks like. I also wonder if this could be some sort of circuit breaker issue??? I'm pretty handy and want to put off the expense of having a dealer diagnose. Any ideas?? It is an electronic climate control unit. thanks Bob

My car did the sme thing (94 850 turbo).Restarting would fix the problem every time. Turned out it was the climate control power stage needing replacement, cost about $150.00 cdn for the part. Installs under glove box easily. Problem solved.

Regards ,

Geoff

Thanks, I am wondering if the "climate control power stage" is the same as the heater motor resistor??

Hi Bobram1,
Can you let me know what the fix turns out to be. I think my 850 has the same problem. My blower motor will not work at any speed for a few days, and then work fine for a few days. Occasionally when I start the car it runs on high no matter what setting it is on. Then when I shut the car off and restart it, it might not run at all.
I cleaned the contacts to the fuse and that wasn't the problem. So I am now taking out the glovebox to try to clean the contacts on the motor.
Any help you can give me would be appreciated.

Thanks,
Tom

Thanks all for ideas. Checked error codes...code 4-1-1..fan or voltage. I have changed fan ass'y. I will check for clean contacts next, then assume it is resistor. Will let all know. thanks bob

The bushing on the squirl-cage side is out and need replacing, you can lubricate it but it wont last very long because the shaft is rusted and there's NO seal against penetration of foreign materials and dust buildup on the fan blade side. I know because I'm working in a electrical shop specialized in rebuilding of electric motors ans it's always the same problem on those blower motors, I fixed mine and others permanently by installing a heavy-duty dust seal on the outside bushing ! A workbench and a hammer and punch to remove the fan blade squirl-cage. I then removed the circlip from the shaft on the fan blade side of the motor and then pryed apart the bushing holder end housing from the fan blade side of the motor. This housing sits in cutouts on the main motor housing and is held there by little ears that are bent over and squeezes the bushing end housing into the slots. You have to knock this housing out of the cutouts by deforming the bushing end housing, somewhat tricky if you dont have the special tool for that. The bushing housing then slides off the shaft and the armature with commutator can now be removed. I sand smooth the outer side shaft because it's rusted all the time, drop a new bushing in the end housing along with the seal and the commutator contacts are cleaned and sanded smooth too. Reassembly is in reverse order..... a 10 minutes operation!
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Dennis

As I've posted before I've had this problem on and off and I think it is due to loose/corroded connections to the motor. This seems possible in your case since you have a new motor which is not probably worn at all. I've kept my old motor running by cleaning everything up a couple of times now. Since the motor, connectors, wiring and resistor all form a series circuit any extra resistance anywhere could act like a bad resistor. Voltage would drop across the real resistor as well as the unintended resistance, lowering the motor voltage to the point where it slows or stops altogether. In speed 4 the provided resistance is 0 and the circuit is partly separate so the effect of dirty connections might be less.

I assume you have a manual climate control. If you remove the kick panel and knee bolster you can check the connections by wiggling them around with the fan switch on. See if you can make the motor start and stop.

Check for error codes in socket B1. Also check if the fan works on high speed. If high speed works, then it is the resistor - located next to the blower. It could even be that the temp sensors are full of dirt, behind the grab handles.

Klaus
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98 V70Rawd(101Kmi), 95 854T(85K mi), 75 164E(173K mi)

Klaus, thanks...Is the resistor to left or right of blower?? What is its shape/color? Also, what are the grab handles?? I sure appreciate it. BTW, I have both Haynes (OK) and Chilton (sorta sucks)manuals. I assume error codes are checked in the little black diagnostic assembly under hood /left front?

bob

The diagnostic boxes(2) are on the passenger side attached to the front of the big black computer box. Your Haynes manual also explains how to read/clear codes. Try page 4-7, there is a pic. The ECC is plug B1. Go to volvospeed.com and look for DTC codes.

The "grab handles" are on both sides of the car above the fron windows. The sensors are behind the little hole.

Volvospeed may also have a pic of the blower fan. http://www.volvospeed.com/Repair/pdash850.htm

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98 V70Rawd(101Kmi), 95 854T(85K mi), 75 164E(173K mi)