Grinding/squeal from under passenger dashboard

[TheBigDinNV]

I am getting a constant squeal/grinding from underneath the passenger dashboard. It almost sounds like a fan is out of balance. it occurs all of the time, heating fans on, heating fans off, AC on, AC off. Anyone have an idea what is under there that could make this grinding and how tough it is to replace said part?

 

[type49]

Knowing what car it is would help

 

[TheBigDinNV]

Well that was a huge DOH factor moment.

It is a 1990 300TE 4matic.

 

[Bolide]

If it's not the heater fan then it's the little fan unit that pulls air past a temperature sensor to control the heating. It's in the dash but I can't remember where exactly

There's a 1/2"-ish rubber pipe that links to it that comes down inside the A pillar. Find that pipe and you'll find the pump. The top end of the pipe links to the sunroof switch / interior lights unit in the roof

Your car may not have an airbag. If it doesn't, pop out the glovebox inner and have a look around with a torch

Nick Froome
www.w124.co.uk

 

[type49]

The little fan Bolide's talking about is called an aspheric motor. However, it's fitted in the interior light unit behind the slatted grill. The main heater fan is in the middle of the dash on this model, so that confuses the issue a bit more. You may have to remove the glove box to narrow it down a bit.

 

[Bolide]

On the car's I've looked at the detector is in the interior light and the fan's in the dash. This explains the rubber tube down the A pillar

Nick Froome
www.w124.co.uk

 

[wireman]

Its behind the glove box, low down on left side wrapped in foam and tyraped to the bodywork on my 124.
Access is through the dash after you take out the glove box liner.

 

[type49]

Two against one, I better back down on this one
It's been a while since the good ole 124 days