Re: Rear defrost not working

[David Boyd <john@dboyd.demon.co.uk>]

You can usually identify which particular horizontal heating tracks are
broken by observing those which remain misted when the heated window  is on.
Very close examination with a strong light behind them will  then reveal the
location of the damage to the tracks, which as Andrew says, can be repaired
by restoring the continuity by painting over with the silver equivalent of
Tippex.
If  *all* these tracks remain misted and there is power to the track
terminals, I suppose every single one of these tracks could have breaks in
them, - can't think offhand of any other logical explanation.

David
****************************************************
john@dboyd.demon.co.uk
Cumbria, UK.

-----Original Message-----
From: Andrew Duane USG/PE <duane@zk3.dec.com>
To: Quattro List <quattro@coimbra.ans.net>
Date: 02 February 1998 13:05
Subject: Re: Rear defrost not working


>Hairy green toads from Mars made Michael Williams say:
>
>> Fluhr decided to speak these words:
>>
>> >Upon further examination, it looks as if the traces are severely
oxidized.
>> >Am I correct in thinking that the traces are made of copper?  Could this
>> >oxidation prevent the defrost from working correctly?
>> >
>> >Anyone know of a safe way to clean the traces without breaking them?
>>
>> Check the switch on the instrument cluster.  On my coupe, it wouldnt work
>> at all, so i took the switch off cleaned it out as best as i could, and
>> if i mess with the switch sometimes, i can get a connection, but that is
>> what it might be.....
>
>The switch is a common failure (BTDT * 2), since *all* of the
>power of the defroster goes through the contacts; there is no relay.
>
>However, since there is 12V at the wires, the switch is doing it's
>job. It could be that the wires are dying. There is a "paint" out
>that conducts for repairing these beasts. A quick trip to Auto
>Palace (or wherever) should do the job for $3.
>
>--
>
>Andrew L. Duane (JOT-7) duane@zk3.dec.com
>Digital Equipment Corporation (603)-884-1294
>110 Spit Brook Road
>M/S ZKO3-3/U14
>Nashua, NH    03062-2698
>
>Only my cat shares my opinions, and she's too heavy to care.