dead radiator fan in Coupe Quattro

[bruce@pwi.com (Bruce Romero)]

Is it possible that the engineers in Germany are still switching 
on the negative side of the circuit? There may be a more elegant
or technical way to state this method but here is what it is:

The current runs uninterupted to the device, through the 
device and then is switched on the ground side of the 
circuit. There is power avialable at all times at the 
device AND the ground leg of the circuit up to the 
switch. It could ground out at any place ("upstream"
of the switch) even though the switch is off.
Any other ideas?

Bruce Romero    '90 V8
brucer@pwi.com

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>From quattro-owner@coimbra.ans.net Mon Jul 31 11:16 PDT 1995
From: schulz@p1045
To: quattro@coimbra.ans.net
Subject: dead radiator fan in Coupe Quattro 
Date: Mon, 31 Jul 95 13:17:37 -0400
X-Mts: smtp
Sender: quattro-owner@coimbra.ans.net
Content-Type: text
Content-Length: 1814

Spent part of my vacation under the hood of my coupe q after the car started 
overheating last week.  Had to drive with the heat on "HI" with temps around 95 
F and 90% humidity.  Nice!

Got the car home, put the AC on, sure enough the temp started going up. Noticed 
that the radiator fan wouldn't come on.  Got out the Bentley, and checked all 
the fuses. Pulled out the radiator expansion tank, moved the charcoal canister 
and the hydraulic (pentosin resevoir). Didn't have the right tool to remove the 
spring "e-clip" attaching the fan to the motor, so I had to remove the motor 
mount bolts and move the motor/fan about in the shround while gingerly working 
around the ABS lines.  Finally got it out.  Found that the ground (brown) lead 
on the three-lead connector had shorted! 

Needless to say the connector was junk.  After cleaning the slightly browned 
male connectors on the fan, tested it with an in-line fuse on the battery.  It 
worked!  Cut back the harness about 4 inches, butt-spliced and shrink sleeved in 
3 -8 inch lengths of 12 gauge stranded wire.  Replaced the connector with three 
female spade connectors, ensured the connection with solder, and shrink-sleeved 
the connectors to the end (Insurance against future shorting) Used the old 
connector rubber boot to recover the new/old connectors.  Put the car back 
together.  Got the car "blessed" by my mechanic the next day.

Question: Has anyone ever had a GROUND wire short out???? I didn't think this 
was possible.  The fan didn't work because the melted connector created an open, 
and therefore incomplete electrical path.

Sorry for the long message, but maybe it will save a fellow Audi owner some 
large $$$ better spent elsewhere than the shop.

Like on more tools!!!

Peter Schulz
1990 Coupe Q with a working radiator fan!


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