Cooling fan still running after key-off

[Todd]

I assume it is a stuck relay but didnt dig in the manual since I was on my lunch hour and needed to get back inside.

Dennis is going to look for me later but in the mean time, does anyone know where the relay is that could stick or an alternate cause???

I am running an aftermarket fan via the factory PWM controller. It stuck on once before for around 20 seconds. Now it will not go off. In the mean time, I unplugged the module from the cars harness to hopefully stop the drain on the battery till I get out of here and drive it home.

[Zack]

I just sent Todd all the info via pm.

[Dragcity]

I thought the fan was supposed to run if the engine bay was hot enough to trigger it on. If it's hot, maybe it should be on.

[TooManyFords]

I just sent Todd all the info via pm.

Thanks for not sharing with the rest of us!

:P

[Todd]

Thanks for not sharing with the rest of us!

:P

It was a link to another site with the MM Manual. Along with the details in the pm. Thanks Zack.


The manual refers to a circuit breaker/fuse in slot 102 in the panel under the hood on passenger side wheel well.

IIRC they look like mini-relays and I assume they are the same. But the circuit breaker thing in the description is throwing me. It says it is rated at 50 amps whereas there are others in there that are lower. I called the dealer and they had no clue what I was talking about and told me to bring it in to look at which part I am asking about.

[TooManyFords]

Out of curiousity, are you actually using the PWM from the plug or just the +12/Ground on it? I ask because I have my custom fan system using the same plug but do not use the PWM features. I just used the +12/ground to power the Flexalite controller I have. This way the Flexalite controls the additional cooling if any is needed and not the car. And, if I may add, I've never had a problem with it being stuck.

I could have used a wire direct to the battery but the old fan plug was hot all the time and it is protected as discussed above. That's why I used it.

[Todd]

Out of curiousity, are you actually using the PWM from the plug or just the +12/Ground on it? I ask because I have my custom fan system using the same plug but do not use the PWM features. I just used the +12/ground to power the Flexalite controller I have. This way the Flexalite controls the additional cooling if any is needed and not the car. And, if I may add, I've never had a problem with it being stuck.

I could have used a wire direct to the battery but the old fan plug was hot all the time and it is protected as discussed above. That's why I used it.


I am using the pwm module to let the car handle it all. I have to get a custom radiator made to sit further forward. then I can run a really thick, high cfm fan setup. Then I will use a external controller.

Which pins are you using in that plug??????







PS I looked at what was in the slot 102. It is a weird, clear little box. It looks like a clear relay. I dont know if that was the problem. I ended up plugging the fan back in and it was off. So whatever was making it run after key off had stopped.

The car was cool when I turned the car off the first time. Water was 192 degrees and trans temp was 149 degrees. Those temps are from a scangauge through obdII port.

[TooManyFords]

Which pins are you using in that plug?
Pins 1 and 2. 1 is hot all the time and 2 is ground. Ignore 3 as that is the PWM pin and 4 is unused.

John

[Todd]

It did it again tonight.

I heard the fan cycling between normal speed and high while in a drive through. It slowed back down eventually (I think) and when I pulled into my garage and turned the ley off the fan continued to run.

This time I just unplugged the harness from the silver control module and the fan of course went off. I plugged it right back in and it did not turn on.

Does anyone have a clue what could cause this??????

[Todd]

Can anyone with a volt meter or test light test all three prongs in the plug that connects the car to the silver control box on the cooling fan???

The fan stayed on again today. I have no clue what would cause something like this to happen or where to start looking. Maybe it is just that little control box.

If a working one has power on one of the pins and the other 2 are dead when the key is off, maybe something inside the control box went haywire. If not, does anyone have any ideas??