Contour Enthusiasts Group Archives Forums General Troubleshooting Rad. fans keep running.

I did a search first.
No matches to the problem.
98 SVT 100K+ miles
Car shut off (no keys in ignition)
Fans kept running until they drained the battery.

Anyone else had the same problem?
What are some possibilites? Wires, fans, etc...

Thanks in advance!

Welded contacts (i.e. staying closed)on fan relay would be likely suspect. Two relays are in fuse box in engine compartment; dark green lo, black hi speed.

Replaced the realys.. problem still exists.
Would the temp. sensor cause this??
Maybe the computer?

I assume both fans are running?
A few things to check,
The PCM relay.
The AC high pressure cut off switch.
If you have a scanner, check the engine temp. Both fans only run when ECT reaches like 220 deg. don?t quote me on that number. If they are running at less then 185 deg. then look
for an electrical short. If the temp reads over say, 230 deg on the scanner (with a cold engine) then check the ECT sens and wiring for shorts.
hope this helps.

jeff

Are you saying that with both lo and hi speed fan relays out of their sockets fans continue to run?

The fans run with the HI speed relay installed.
Pull out the relay and the fans stop. New relay!

As for the one post about temps. recall the car is not running or on. Are these fans set up to kick on even with the car off?? I know Honda and others do that.

Will it damage the car to drive with the relay pulled out?

Mmmm!
If I interpolate your comments; fans do not run with lo speed relay in and hi speed relay out. Therefore I'd keep the hi relay out, lo in 'til you've solved problem. To ensure no problems keep an eye on temp guage, and minimze a/c use. (easy for me to say it's 33 F degrees here, coldest in 50 years).

I'm working with '97 Ford wiring diagrams and there could be differences with your '99. Operation as follows:

Operation should not be possible with ignition off as +ve feed to both fan relay coils comes from PCM relay which is fed from ignition relay. Inputs to PCM (temp and a/c) 'cause PCM to provide ground to hi or low fan relay coil. Fans derive +ve feed from fused battery connection via contact on fan relay. Therefore as suggested in earlier post, if fan relay contact is welded closed fan will operate.

One curious thing in Ford manual is that hi fan relay connector pin-out shows pin 1 as PCM and a/c switch, but this is not shown in circuit diagrams. A simple test would be; with engine off, release locking tabs and pull off the connector (c118) to this switch located at pass side engine compartment and see if fan stops.

Further troubleshooting to isolate problem will require multimeter, with one exception. If you feel able/willing to seperate hi relay cover from its base you could insert a small piece of paper between its contacts, re-assemble and insert in socket. If fans did not operate then problem would be in coil circuit. If fan continued to operate then fans are receiving +12 volts from somewhere they shouldn't be. Latter would be preferred fault to find.

p.s. Did you have any work done on car immediately before this problem appeared?
p.p.s. Sorry you went and bought new relay(s). I would have checked contact continuity first after removing from socket.

Fans on my cars run together, hi or lo speeds, earlier models had 2nd fan come on with a/c. FYI.

Yes. With the lo relay in and hi out... fans stop.
With the lo in and the hi in fans run constant.

No previous work was performed to cause this.
I've opened the relay and see no "contacts"
there is a large coil and a resistor.
Since I used a new relay wouldn't the problem be upstream somewhere? AC switch, ignition relay, PCM, etc...

Looks like I have some work to do!
Thanks again for the help.

Hmmm I wonder if your problem is any way related to mine. When it has been raining hard, my fans come on and stay on for as long as the car is running but they do shut off when the car is turned off.

Obviously means that I have water going into some harness that causes problems. I dont suppose it was raining when you experienced your problem.... ??