Vauxhaull Corsa Turbo - Windscreen Heater Screeching - Lynne MacNicol

When the car is particularly cold at start up (less than 5C outside) as soon as i put the heated windscreen on there's a really loud screeching for about 30 seconds then it tapers off. It's only 2 years old and still in warranty so it was checked out last year but at the time I thought it was the heater and they couldn't find anything wrong. I can take it in again but if they don't find anything wrong then I'll be liable for the diagnostic charge. Has anyone any idea what it could be?

Vauxhaull Corsa Turbo - Windscreen Heater Screeching - Metropolis.
Most probably the HVAC fan, but I suggest recording it as it happens, then sending the video to the dealer before taking it to them. Make sure the sound can clearly be heard in the video and get them to acknowledge in writing (email) that it is not normal. The cost of diagnosis and repair is then entirely on them, or as much as it can be save for something caused by user error, which I don’t think is the case here.
Vauxhaull Corsa Turbo - Windscreen Heater Screeching - elekie&a/c doctor
Where is the screeching, in the cabin or under the bonnet?
Vauxhaull Corsa Turbo - Windscreen Heater Screeching - bathtub tom

I'd guess fan belt. Use a trigger spray to squirt water (nothing else) on it when it's screeching. If the noise stops, there you have it.

Vauxhaull Corsa Turbo - Windscreen Heater Screeching - Lynne MacNicol

Soundslike it's coming from under the bonnet.

Vauxhaull Corsa Turbo - Windscreen Heater Screeching - Lynne MacNicol

Thanks I did try to record it last year but was hard to hear it on the video. Seems to be slightly louder this year though. The garage thave told me to let it get progressively worse then get it checked out but I don't want to do that.

Vauxhaull Corsa Turbo - Windscreen Heater Screeching - Oli rag
I would agree that it’s probably the auxiliary belt slipping when the alternator is working hard when you’re using the heated screen. These really do use a lot of current.

Tighten the belt or preferably replace it.
Vauxhaull Corsa Turbo - Windscreen Heater Screeching - blindspot

fan belt or leaves sucked in and stuck somewhere

 

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