fuse therapy session....

[johnholt at sympatico.ca]

1990 Canadian Coupe Q 20v (with inoperative air conditioning but that MAY
not be relevant).

Bentley and Owner's manual says - Fuse 18 should be for rear windshield
wiper and power mirrors including heated mirrors. Fuse 21 is for
diagnostics.


Real life - Rear windshield wiper and power mirrors including heated
mirrors is not fused on fuse number 18 but rather fuse 17 with fresh air
blower and air conditioner. In theory, I don't need fuse 18. No apparent
screwing around with circuits by PO.

.....and fuse 21 blows with regularity.


Condition - When fuse 18 is inserted, the air conditioning control head
remains in "on" position with red indicator light at whatever setting prior
to key key being removed and blower operating despite the fact that the key
is removed and the owner has walked (guaranteed dead battery syndrome).

Removal of the fuse 18 kills the "on" problem and the air blower/ac head
acts normal and turns off with key. No unusual problems in diagnostics.
When fuse 18 is re-inserted and key is turned on, the ac head problems
return. If key is turned on and fuse 18 is then removed, I hear a
switch-off sound around mid to passenger side of engine. Haven't found the
sound yet (compressor???)


Logical Solution - remove the number 18 fuse and life is normal.

I can't accept that and so before I dig further, does anyone have any
insight into the purpose of fuse 18 and/or why the diagnostics fuse 21
constantly blows.


Appreciate some help. TIA

John.....