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Radiator fan-1990 200tq Help

"Ron Frazier" <frazierx@concentric.net>

My 1990 200tq is overheating.  The fan does not cut on under any
circumstances as far as I can tell.  I disconnected the fan and powered it
up with a 12v battery charger at 3 amps and the fan cut on and ran. I also
switched the the 3 relays around to see if any were bad but nothing showed
up.  I also checked the fuses. when I cut on the car, turn on the
airconditioner and the fan does not come on.

A typical 44-chassis problem.

The 3-stage, 2-section ballast resistor is fried. It's mounted on the FL
longitudinal member and looks like a piece of anodised (blue or red) Al angle,
~20cm long x ~10cm ea side. Three thick wires are coming out of it. Disconnect
wires, test sections: ~0.5 ohms ea. I betcha one section will show infinity.

  The after run cycle of the fan
did not turn the fan on when the car got overheated.  The wiring diagram in the
bentley manual is a little complicated.  What does the radiator thermo switch
If <93C - open, if > - closed. Pull it out, connect an ohmmeter across it and
dip it in a pot with water. Boil the water, check the operation.

When i was leaving work,heading for the highway,
the AC would not put out cold air.  But after I got down the road I turned
on the AC and it put out a lot of cold air. I guess the AC is related to
Engine Temp.

Your main fan is not working hence ther's no forced cooling of the hot side
(condenser) => no cooling on the cold side (evaporator).
Once you get moving you get forced airflow through the evaporator the AC starts
to produce cold air.

  As best I can remember the turbo water pump [...] runs after the car is turned

So your rad fan switch is OK. Check the resistor (see above).
Igor Kessel
'89 200TQ -- 18psi (TAP)
'98 A4TQ -- mostly stock
Philadelphia, PA