1990 RRC: Heated rear window affecting door mirror operation

Richard Savage

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Dec 20, 2009, 2:17:47 PM12/20/09

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Electric door mirrors move in the appropriate directions under control
of the dash joystick switch until I operate the heated rear window
switch. Then left and right operation of the joystick moves the
mirrors up and down. Also, I think that the heated rear window
doesn't heat. This is difficult to tell as the RR is sooo damp at the
moment that I wouldn't expect a fully working HRW to make an
impression. FWIW the radio reception is fine. Oh, and when I turn
the HRW off the central locking solenoids 'jump'.

Any electrical wizards who wish to make encouraging suggestions are
very welcome to do so!

TIA

Richard

EMB

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Dec 20, 2009, 2:19:40 PM12/20/09

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It sounds like there's a faulty earth connection somewhere.

G8KBV

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Dec 21, 2009, 5:13:27 AM12/21/09

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In article <c8531fd4-3ad6-4530-a0cf-7f0c908f6996
@m16g2000yqc.googlegroups.com>, r...@nildram.co.uk says...

Dry it out, then go looking for Lucas Prince of Darkness problems.
Dodgey connectors, corroded and or leaky.

In particular, check and re-check all the earth (to body) ground
connections. Many "odd" automotive electrical woes are often down to a
ground, that isn't as "groundy" as it used to be.

Idealy, you need a 4 terminal ohmeter, but removing, cleaning and re-
assembling them is a good move. Any bad ones, & you'll find them that
(if tedious) way.

If you have a manual with a full schematic. Try to identify any
"common" grounds that serve all the seemingly affected (and eroniously
interoperating) systems, and start by looking at them.

Have Fun! ;-)

Dave B.

Bob Hobden

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Dec 21, 2009, 7:14:33 AM12/21/09

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"Richard Savage" wrote

Could possible be the old "earthing " problems, a lot of us chaps with old
Landies have put in extra wires connecting the main earths together and back
to the battery so not relying on earthing through the engine/vehicle. Made a
difference to my vehicle.

--
Regards
Bob Hobden
1986 90 Utility 2.5 petrol

Lee_D

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Dec 21, 2009, 1:35:26 PM12/21/09

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"Richard Savage" <r...@nildram.co.uk> wrote in message
news:c8531fd4-3ad6-4530...@m16g2000yqc.googlegroups.com...

I had a Granada Scorpio ('93) that got a flooded Fuse and Relay box, the
result was equally spectacular , I had a very Random Disco, Random Sun roof,
Locks , Lights and windows. Oh what fun!

Whilst Earths may be the root... I'd be looking at the next common link
between all the devices you are having fun with. Fuse / Relay boxes.

Lee

Richard Savage

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Dec 22, 2009, 6:01:27 PM12/22/09

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Thanks to all.

I really hoped someone would say something like: 'ha ha that'll be a
faulty wotsit made of unobtanium' so that I could happily ignore the
problem. I really don't fancy chasing earth faults - which is what I
expected you to point to. I do have the wiring diagram as bedtime
reading.

I suppose it's as good a way as any to spend Christmas day <sigh>

Alternatively I could try to create a CAD version of the wiring
diagram to make it just a little easier to read.

Richard ;-)

Richard Savage

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Jan 1, 2010, 10:26:40 AM1/1/10

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Well I suppose it's always best to try the most difficult and time
consuming checks before starting with the b********ing obvious ;-)
Grovelled around trying to trace Earths etc then got bored and looked
at the HRW connection with a meter. The lead which connects power to
the screen had fractured in the wretched tube-thing at the top of the
rear window. 20 mins careful work with a soldering iron and heat
shrink sleaving plus a little work with cutters to remove the cables
to the non-functioning tailgate lock and discarding the tube thing and
Bingo: nothing.

Arse! I then replaced the blown fuse in the dash ;-(

Mirror operation still entertaining but at least the Chinese laundry
effect at the back is controllable. Next task is repairing a break in
one of the HRW tracks.

Happy New Year to all

Richard