RE: 164 overheating reminder

["Karl Chen" <karlcchen@xxxxxxxxxxx>]

The fan failure has no direct relation with cooling system.
A bad cooling systen may cause fan to kick in more often than
normal but should not cause fuse to melt.
The most times when this happened it is the DC fan motor
cannot spin up quickly enough (bearings or other external force/object
prevent its spin up), this force it remained at high current draw for too
long and the fuse is finally melt.  A DC motor at standing start will always
draw very high current, sometinmes a resistor is used in series
to limit its current draw at starting.  This also protect the DC motor
from over heating if starting is often.   Overheating can shorten the
bearing life of a motor. This is why I do not like the idea of removing
two speed fan resistor.  With two speeds, the lower speed kicked in
first most of the time and if necessary the high speed (without go thru
the resitor) will follow.

Your fan bearing could be on on its way out so even with new fuse this
could happen again.  If this is the case the only cure is a new fan motor.
I had fan fuse blown on me twice on different cars( 92 VW Corrado and
92 Alfa 164S ) and both times when I checked the fan bearings they are
not good so a new fan motor is the better solutuion for me.  Sure, a new
fuse with some luck the DC motor may survive another year.  But it
may also happen again in a few days.   Do not use higher rated fuse
to by-pass the problem.  Fire could happen.

The fusible link can tolerate rated current longer than the quick melt
blade type fuse used in fusebox.  The blade type fuse is also not reliable
over 30A because of its contact design.  The fusible link using screws
to tighten contacts can be safely used in higher current.

Karl Chen

> >
Date: Sun, 20 Jul 2003 17:42:29 -0600
From: C M Smith <cmsmith@domain.elided>
Subject: 164 overheating reminder

The great resource represented by this digest and the 164 Tech discussion,
as well as the home page references paid off for me again on Friday.

My wife reported a sudden overheating event on my 164, boil over etc. She
parked and shut off immediately, bless her.

Reminding myself of the short but painful list of deficiencies in the 164
cooling system lead me to check the 40 amp fusible link on the false
bulkhead first. Sure enough, this weird little component was neatly burned
through. Why Alfa can't just use a regular fuse is beyond me though.

A quick trip to the local auto parts store and some jury rig work with bits
of heavy gauge wire, crimping tool and U shaped and blade connectors got me
a temporary 40 amp fuse to tie in behind the terminal posts. All fixed,
until I can visit 'Sandro and get a proper fusible link.

In order, assuming the radiator is fine, the water pump is fine and
running, the coolant expansion tank isn't cracked, and the heater core
isn't leaking, I would check this little component first, then the rad fan
switch (which can be jury rigged by bypassing it with a jumper wire) then
the relays, then the low speed fan resistor.

Cheers

Michael


Michael Smith
White 1991 164L
Original owner

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