Intermitant Heater operation W124 E200 no ac

[w123robbo]

Hi Chaps i have a lovley old 123 230E and a nice W124 E200 both low milage 60000 each. The W124 has an intermitant fault with the heater blower.Sometime it works ,sometimes it doesnt.sometimes it seems to be turning slowly othertimes fine.Messing with the switch does nothing .The fuse is fine ,the Blower sound fine when working ,but its a lotterey as to when it will.Does it sound like the switch? Weird as if it was broken I guess it would never work,it seems to have a mind of its own.Any ideas ? Does it sound like something is breaking down or anyone had anything like it before? Thanks in advance. Still love the W123's and W124's!!

 

[stumpy]

Have you checked the fuse?

 

[w123robbo]

Yes but will get a new one ,I put a spare in but it was one of the spares that came with the car from new so may have broken down but its the erratic nature of the problem that gets me!

 

[television]

The carbon brushes in the fan motor can cause this, as can a dirty poor contact switch

 

[w123robbo]

Thanks so far !! Impressed with the Rapid responses!!

 

[wireman]

The fan is a bit of a pig to get at, first check the fuse holder and fuse especialy if they are the older cylindrical type with metal (ali or copper) strip laid along its length.
The ali type in particular tend to corrode at the contact points in the holding clips. This leaves a film of non conducting stuff on the holder which will easily break up if the fuse is moved but it can/will regrow and the problem resurfaces.

Clean up the holder and fit a new fuse first.

Beware of the copper material used in the fuse holder, I am not sure but it may be CuBe - a superbly springy bronze material commonly used in higher spec electrical components, it does look the right colour for it.

The berillium part of CuBe is very toxic, any rubbings or filings can enter the skin and even in micro gramme quantities can wreak havock with it (give it a week or two then expect excema, green puss and even later on cancers), if you need to abrade the clips make sure that you do not get any metal particles into your skin (or the rest of the electrics). The material is safe to touch but not safe to have inside your body so wash well after contact.

If the fuse box lid is not correctly fitted and closed the damp will encourage this kind of fault.