1991 W463 300 GD Heater motor
Hi there
About a year ago my heater motor starting changing speed at its own will, if i twisted the switch to 3 it would be ok for a while but then would vary the speed. A few weeks later i noticed that there was a strong electrical burning smell coming form the heater, I assumed that the motor has burnt out.
However, i have been looking at the few forums which say that i must check the resistors etc first. On my G there is a plastic covered mount in front of the battery which has about 6 cables coming in and out, is this resistor mount?
Any help will be much appreciated.
Regards
Adam
Heater fan Rheostats for diesels are usually mounted either front face or towards the near-side of the vent housing on the bulk head of the engine compartment. Hence in between the battery tray and vent housing or box.
http://fourbyfourclub.com/W460ElectricalParts/W460BlowerResistor1.htm
The image in the above URL will give you an idea of what the unit looks like, although I had thought the bear coiled wire you see in the image was covered with a multi-holed metal guard. If you are able to by-pass the rheostat try supplying a direct feed to the motor and that would be the quickest way to test the motor out.
Adam, I don't think that is the heater rheostat unfortunately, on my 1991 it's in the middle of the heater , meaning major stripdown, bad news, though you could check the switch 1st
If the Rheostat is not in between the air vent housing and battery tray then most certainly you will find looking at it from the near-side of the passenger foot well. On some models you can view it mounted on the exterior of the fan motor cowling; in others this is internally mounted and access to it by a complete strip. You will need to remove the passenger foot well cover which covers the fuse area.
To replace motor if needed requires extensive strip down of the dash.
Hi Smithy,
I have the same problem (although mine is a petrol). I've been putting this job off as the words "complete stripdown" etc. strike the fear of God into me so please let us know just how difficult, time consuming and maddening it turns out to be. Maybe your experience will persuade me to get on and do it too.
Have you got Air Con? Will be worse, if so. It's not too bad, but a lot of self tappers hold the dash in place , take lots of photos , the centre panel that houses the switches , take lots of notes when disconnecting that, diff lock lights easy to mess up, all looks a right mess when removed. Are you going to buy a new motor or repair rheostat?
Does anyone have any experience of this company and the replacement blower? It seems the cheapest around from a quick search but are they any good?
This seems to be a UK version of the site....
Thank you for both comments.
I have looked in the engine bay and the only thing I see in between the battery tray and the vent is the wipers motor. I will test the switch later and see what's what.
Assuming this is going to be a strip out to get to the motor are there any technical articles that assist with this job?