Heater Blower Motor/Resistor

[BikiniAtoll]

Hi everyone, I was enjoying a nice wintery drive today with the heater on max. It had only been max for a few mins then all of a sudden it cut out and there was a burning smell and a few whisps of smoke emerged from under the passenger glovebox.
Presuming the motor has gone but wanted to get your thoughts on it - just due to where the smoke came from - might that indicate it’s not the motor? I had noticed some fogging when the heater first comes on warm over the last month, perhaps water getting in somewhere.
It’s a 1990 Scirocco GT2 btw!
Thanks in advance!

[GT_II]

Smoke from under the dashboard suggests there is an electrical burnout somewhere around the relay board, possibly due to water ingress, as you suggest. The drain outlets from the plenum chamber into the wheel arches may have become blocked over the years by leaves and muck, causing water to build up and enter the dashboard area via the heater fan. That would be consistent with the misting up you have observed, though a leaking heater matrix might be another possibility I guess

[BikiniAtoll]

Hi all! Just an update on this. I checked the fuse and the one for the blower was thoroughly melted and took some prising out. With a new fuse in the heater is working again although I have been seeing the occasional smoking again. And when the heater is on warm the passenger side windscreen fogs up immediately. This doesn’t happen when it’s on cool. Pic below. Does anyone have any thoughts on this? Thinking it’s definitely water getting in somewhere but would it be the motor or matrix or somewhere else entirely? I unblocked all the drainage holes in the plenum chamber a short while ago so don’t think that’s where the water is coming in…

IMG_5748.jpeg

[craigwalton]

I had an issue with rain water getting into the passenger footwell and am 90% sure the source was the blower motor despite the drainage holes being clear. I formed a generous silicone damn around the return of the cutout where the blower motor sits and haven’t had the issue since. Might be worth a shot! I never had electrical or smoke issues though.

[GT_II]

As far as I know, the plenum chamber is the only possible route for water to get into the heater system (other than through a heater matrix leak, which would result in loss of coolant). Have you checked the entire plenum chamber for debris? If the car is on a sideways slope, the rain water needs to flow from one side to the other. Also, are there any cracks in the plenum chamber cover which could allow water to drip directly into the heater?