Billdavis83

I am having troubles with the cooling fans on my 85. I have both a pusher and a puller fan. Neither will turn on when the car gets hot. I replaced all the coolant switches on the motor.

I was going through the diagnostic section in my Haynes book and it said to jump terminals A and D on the relay harness. The problem is, my harness does not have a terminal D. Nor does my relay. If I jump terminals A and E, the fan runs. Any ideas what to do next?

Also, my book mentioned if there is an auxilliary pusher fan, there is another relay mounted on the shroud. My car does not have this relay.

Help please

cutchy

You should be jumping points A and B on the ALDL connector under the dash. Jumpered and key on will cause the main fan to turn on.

As far as the smaller fan mounted in front of the radiator you should be able to force it on by having the car running with the A/C set to max.

You said you replaced all the coolant sensors and switches but a quick test of the switch located on the passenger side head between cylinders 6 and 8 will determine if the switch is your problem. Just jumper the connector to ground the main fan should come on immediately. If it does then the switch is your problem. If it doesn't start tracing that wire back to the ECM.

Don't be surprised if the car gets pretty hot before the fan is turned on. I think mine switches around 215.

jfb

First check the 3 amp C. Fan fuse with an ohmeter! The ECM turns on the main fan at 228 F and the switch in the block between cylinders 1 and 3 turns on the auxilliary fan at 238 F by grounding one coil wire of the fan relay. The relay for the auxilliary fan is mounted behind the LH parking light If you ground the green/white wire on either fan relay, this will close the relay and the fan motor should run (ign sw has to be in run position). Also, to test the fan motor itself, jump 12v to the large black/red wire on the fan relay or unplug the motor and jump 12v to the motor plug. Also check for corrosion under the ground terminal for both motors and clean it to bright if cruddy.

86PACER

I went through this too. If 85 wires are the same, you should jump A and E as you did. This closes the circuit and gives the fan battery voltage like what the relay would do. The Haynes is incorrect.

What you need to do next is see if you are getting battery voltage to terminal C(Dark Blue) of the relay connector with the key in Run and check the C. Fan fuse. Also check for continuity between the relay's B and C terminals with an ohm meter.

If you are getting battery voltage at C or there is no continuity between the B and C terminals of the relay, your relay is bad.

CentralCoaster

Here's the wiring. Ignore the override switch I drew on there.

86PACER

Interesting. He say's his 85 does not have a D terminal, but has an E instead like my 86. Your 85 wiring diagram shows it should be D in 85. Wire colors match though.

CentralCoaster

I'd trust his eyes more than the manual. Theres lots of little inaccuracies between years. The relays all have 5 terminals.. only 4 are used.

86PACER

Yep. One more reason why I do not like the Chiltons having all C4 years rolled into one like that.

CFI-EFI

How hot? The engine has to get pretty warm for the fans to come on. I think the temps were listed above.


That Haynes manual is good for oil changes and grease jobs, but it tries to cover too many years. Get a factory service manual for your 1985.


The switch in the right side head, between the #6 and #8 spark plugs is the AXILLARY fan switch. The main fan will not come on if it is grounded. The auxillary fan should, however. The main fan is controlled by the ECM. The ECM gets it's engine temperature information from the ECT sensor in the front of the intake manifold. The ECM uses that same sensor for ALL of it's temp related functions, such as a rich, cold start mixture, and a fast, cold, idle.

RACE ON!!!

MrRenoman

CentralCoaster, nice job...you frequently post with nice links and pics. Way to go

Art

Billdavis83

So if I jump my E and A terminals on the wiring harness and the fan turns on, then is my relay bad?

86PACER

Not just yet. Read post #4.

Billdavis83

Just to make sure, does key in the RUN position just mean in the ON postition? Also, don't know if it means anything, but when I turn the key to start the car, the fans turn on. I noticed this when my clutch positioning switch was out of adjustment.

86PACER

Run means key on, but engine not running.

Billdavis83

Great, I'll try it this weekend. If I can get the fans running, maybe I can drive the damn thing. Been about 2.5 years. (building engine as I got the money)