rad fan wont stop

[Tom Christiansen]

Brian,

>I have an '87 5K turbo and I can't get the rad fan to NOT run all the
>time.
>My dealer told me that there are a set of 3 diodes located on the frame
>rail that also controls the fan.  Does this sound right?

They aren't diodes, they are resistors. And judging from your description
they also work! The resistors are located on the LEFT frame and look like a
piece of angle iron (typically blue or pale green) with three studs/tabs
coming out of it. The studs have some rather hefty (8-gauge, I'd think)
wires attached to them. If the resistors are bad, the fan will only run at
the highest speed.

If I remember correctly, there's a separate thermal switch controlling the
fan. I forget if the switch controls the fan directly or if it goes through
a relay. I bet either the controlling thermal switch or the fan relay has
gone bad. Also note that if you have the AC on, the fan will come on at the
lowest speed when the ignition is on regardless of engine temp.


Tom