Rear Demister - 107 (1988/89)

[30471]

This fails to work and my service guys are suggesting that the only remedy is to replace the rear windscreen.

Apparently a sign of a faulty windscreen is to see faint white smudges on the heat coils in the screen. There are none.

There is a current passing from the on-switch through the lead and on to the connection but my service guys feel this is low at 2 amps. Further advice has said that it is normal that this failure happens and at best the rear demister is slow - Any one had the similar problem ?

Can anyone assist in suggesting a remedy rather than the drastic solution so far provided.

 

[TimN]

You may find that the copper rails to eitherside of the window are seperating from the elements on the winscreen itself. Pull back the rubber surround. The copper strips should sit snuggly against the glass. If they don't then the contact may be broken or resistance in the form of corrosion may have built up. A strategically placed blob of solder amy remedy the situation but the glass must be clean.

Gaps in the element can be repaired by conductive paint but often look a mess afterwards.

Have a look at the earthing point. It might have gone rusty. Try a new supply and earth to see if it works okay. Could be the switch?

 

[Andy]

Hi

This system is pretty standard. Make sure your electrical feeds are ok, and earth is good. There is a relay. Can't think where it is at the moment. But rear windows do play up.


Sorry I can't be more specific

Regards

Andy @ www.mercedesservicing.com

 

[wrichardson1999]

Havin a similar problem, light comes on but no bodies home ;-)

Tried looking for connections in the boot for the rear screen, any help guys, need to trace why it's not demising

Cheers