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Re: Injector Cooling Fan & Aux. Coolant Pump Update
> Well, a long time ago I promised that when I started troubleshooting the
> injector cooling fan and after-run coolant pump on my '86 5KCSTQ I would post
> results to the list. As of this weekend, here's the scoop:
> The thermoswitch that controls the injector cooling fan apparently is bad.
> This is the switch on the heat shield just about four inches in front of the
> wastegate (towards the front of the car). This switch is a grounding switch
> - it connects the fan to ground, so it only has one wire. Removing the wire
> and grounding it against the body of the switch causes the fan to work on my
> car, so I will be replacing the switch. Glad the fan motor isn't blown.
> Helps to troubleshoot this with a cool engine. One down, one to go.
> The after-run coolant pump was a little more problematic. I pulled the
> connector off the pump and connected a multimeter to it. With the key off,
> the connector reads 11 volts, constantly, engine cold or warm. Left it
> attached to see if the relay disconnected it eventually...15 minutes later
> (key off), this doesn't happen. Reconnecting it to the motor, nothing
> happens either, so I suspect the motor is toast.
> Remove the connector again, switch on the key with the multimeter attached,
> voltage drops to 0 at the connector. This is probably as it should be. I
> think the relay that controls the pump went bad, (or else the thermoswitch
> that controls the relay that controls the pump is bad) letting it run
> constantly and burning it out.
> Now the problem is finding the relay. Looking in the Bentley, it says the
> relay should be in Auxiliary Relay Panel I, underneath the steering column,
> right next to the interior-light delay control unit. Removed the parcel
> shelf and lower covers, located the light control unit (felt the click when
> interior lights go on/off) however, the next block contains no relay,
> instead it has a wire connector block with two connectors attached. In fact,
> there are no other relays in the block, just connectors.
> So, the control relay must reside elsewhere. I suspect the passenger's side
> dashboard, behind the A/C programmer (Where Aux relay panel II is supposed
> to be according to the Bentley).
> Pay heed to the Bentley when it says things like:
> "Actual locations of relays may vary according to model year and individual
> Are any two of these cars alike????
> Also: I picked up the trick S6 radiator cooling fan from a nearby dealer.
> It looks like it MEANS BUSINESS. It has about 10 scythe-shaped blades and
> resembles a turbine. I'll bet it flows a ton of air. The parts guy looked
> at it and said: "If you hadn't picked it up today this was going on my car."
> $40 bucks. Now I just have to get the $*!^$% fan motor out so I can put it
> on. Then I can get the other cooling systems working and I will fear the
> heat no more! I've been reluctant to drive the car in the 95+ degree weather
> we've been having without these components working properly...the underhood
> temperatures once you park the car are astounding. The injector cooling fan
> is there to blow air around under the hood, too.
> Finally, while I was underneath the car I noticed that the little horn
> attached to the front of the airbox that is supposed to help the car breathe
> cool air (it curves away from the turbocharger) was melted straight through
> by the turbo's heat. Oh well. I removed it. In about a week or so (they
> say), TAP will have the K&N Cone filter conversion available to replace the
> stock airbox, so I'm not too worried about it. No more filter changing
> hassles and they promise 12 extra horsepower. We'll see. Also, there is a
> lot of gunk trapped between the A/C and the engine radiator that I will be
> brushing/flushing out before I button everything back up. Take a look in
> there on your car and you might find a bird's nest or Jimmy Hoffa or
> Best wishes,
> Alex Kowalski
> '86 5KCSTQ
I had the same trouble with my aux. coolant pump. I took the pump
out,applied 12V to the terminals, and it wouldn't turn, but a large
spark! Bought a new pump, plugged in, nothing. The relay had burned
out due to a seized pump. the relay is brown, with black felt on one
side. It's plugged into a brown socket, under the steering column,
slightly to the left- can be reached through relay panel access
door-very tight! You might want to just lower the panel. I kept the
old relay, and one rainy day, will try to replace the burned out
component-it's charred inside!
Good luck, and the parts are expensive!
San Ramon, CA