Heater Blower Motor or something else?

[Audi 80 Man]

Hi All,

Can anyone advise what the problem here might be......

Start car, drive up road, and turn heater on (no air con in this old timer Audi 80). Sudden pop and electrical burning smell and heater (blower) not working (but heat still being generated). Turn heater off and continue to destination

At destination check for heater fuse. Sure enough, it's blown. Replace fuse, start heater, fan is blowing but some faint smoke comes out of the vents and the electrical burning smell is still there so turn unit off.

When I get home remove glove box to get at blower fan as I assume it's that failing. Remove fan and run it "freestanding" for want of a better term (i.e. not connecting up into the vents/system.

No burning smell, fan runs fine at all speeds, doesn't make any unusual noises. If I spin it with no power if very quickly stops rotating. Turn it off and reconnect up into the vents/system. There doesn't appear to be anything rubbing or any cables shorting out

Turn it on again, runs fine for a few seconds, no smoke now or unusual noises, but then the electrical burning smell starts again. Turn it off and remove from system and test again.

Same result, including when I reconnect it to the system and the burning smell.

I assumed it's the fan failing but it seems to be running fine when not all hooked up so: is it the fan packing up, or something else?

Very puzzled as all seems fine when it's running freestanding.

Help/ideas gratefully received.

Cheers

[scotty33]

Hi All,

If I spin it with no power if very quickly stops rotating.

Cheers

When it is installed in it's housing, there will be more load on the motor, as the impellor will be shifting some air. I would guess that the bearings are 'dry' and it is starting to seize up as they get hot. If you can get a few drops of oil into them it may work ok until the next time? Have you checked that the air inlet is clear?

[Audi 80 Man]

Ah, yes, that's a good point (about more load). I have tried some oil in but still no joy so phoned all the local scrappers etc and got one from from a 90 quattro. But with that fixed (and am pretty certain it's only occured since the fan packed up) we're on to the next problem...

https://www.vwaudiforum.co.uk/forum/s...925#post111925