V8 cooling

[David Head]

I removed the instrument cluster this morning and removed the fan
control circuit board. This board is mounted directly on the back of the
instrument cluster and can be removed without dismantling the cluster
itself. The cover has 3 screws that hold it on. When removing the
cluster, you'll spot it by the 2 pin connector that plugs into it.
It has about a 20 pin connector that plugs into the Autocheck board.
Careful prying with a tweaker on both sides and it comes right out.
Although I had previously ordered the correct replacement chip from
Digikey, I remembered John Cassarra had shown me a spare cluster he had
up in his garage attic the last time I visited him. Since I was heading
up to Atlanta anyway and knew he had sold his V8 a while back I gave him
a call and we made the deal. I still have an Autocheck problem to
troubleshoot in the other V8 and the spare cluster will come in handy.
Eyeballing the 2 cards, I noticed the later one from the spare (12/89)
was missing a resistor that mine had (5/89), and had a larger power
transistor. The red V8 is a very early US production model (build date
6/89), and it appears VDO was already incorporating some running
changes. When I get around to pulling the cluster in the lago blue car
to do the Autocheck work I'll compare that board also - then maybe see
if Scott Mockrey wants to play around with it to see if there are some
improvements to be made.
After putting the cluster back in, I hooked up the 100 ohm resistors to
each sensor. This gives a signal of about 118C (I've exceeded that while
sitting in traffic - no pleasant experience!). All 3 fans speeds cycled
through perfectly. Awesome! Its nice to hear the hurricane of the 3rd
stage - same sound as the 200.
I've previously added a 16" pusher fan in front w/thermostat. I'm not
expecting any more cooling problems. When we do the timing belt shortly
we'll be replacing the water pump and thermostat as preventive
maintenance items also.

Dave Head
90 V8q - 76K
90 V8q - 107K (the hanger queen)
90 V8q - IC - 4512 miles... :-)