How do I ensure fan motor is bad?

F

fernleybjk

Registered
I have a 98 LSC and the other day it overheated. It did not enter the red zone but was close. It was flowing out of the reservoir tank. I added some coolant to the reservoir tank ( I now know that is not the proper way to add the coolant) and drove home. Actually I drove home with the a/c off and it did not move past the mid point. I immediately did some research on the posts and realized that the radiator cooling fan was not turning.

I checked the voltage at the connector and it read 13.2 Vdc. I also learned that the fan turned on by a signal from the VCRM. Someone suggested that you apply 12V directly from the battery to the fan terminals. If the signal isn't there from the VCRM, then how does applying 12V from the battery signal the fan to start?

I found some complete fan assemblies from car-parts.com (thanks to information supplied from Whiplash). How do the junkyards ensure that the fan is working? The fan blades rotate freely on mine so they are not seized up.

Your help is greatly appreciated. Thanks!
 
Hooking to 12v directly only eliminates the fan motor itself from being your problem..... you might wanna check out the connector tho....
 
steve said:
don't forget to pull the fan fuse and check it.
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+1 I always remember to check fuses....last.


Another thought. If you disconnect the lead that goes to the fan, and the motor doesn't fire up by connecting 12v directly to the terminals, I'd say it's a safe bet the fan is bad.

It may be work asking in the "parts wanted" section of this forum, as somebody here with a fan to sell, would also likely have the means to test it. I would hope that car-part would at least offer some sort of warranty, but I would assume that it would be impractical for them to actually test the fan before sending it out.
 
checked fuses in engine compartment

checked fuses in engine compartment

I was not sure which fuse was for the fan so I checked all of the fuses that I could in the engine compartment. They Ohmed out good.

Some one stated that the motor was attached in some manner that if replaced would required drilling, etc. to attach new one and that it would be simpler to replace the entire assembly. Has someone done this on a 98 LSC?

I checked the connector pins and none were corroded. I also tried to wiggle test to make sure it wasn't a bad connection.
 
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I've never had to replace it on my (97) Mark, but I swapped one on a buddy's '95 Cougar a few years back. if memory serves, it was two bolts at the top, and the bottom just had protrusions that nested into some holes. it was a pretty easy swap.

If you have power at the fan connector when the fan *should* be on, I'd be tempted to yank the fan, and test it separately. I have heard others here talk about the fan connector failing, but in the case of yours at least, the signs seem to be pointing to the fan motor itself being the culprit.
 
When my fan went, the motor seized up. You couldn't easily spin it by hand. It also took out the fuse at the same time since it took too much current to try and spin it.
 
The fan conenctor has been known to become intermittent. Check for any arcing (burning) on and in the conenctors.
 
Replacing the fan motor itself is not that hard at all. You can do it in under an hour.

Any junkyard one may be good, but how long will it last?

I've gotten new fan motors from NAPA and Rock Auto.
 
driller said:
Replacing the fan motor itself is not that hard at all. You can do it in under an hour.

Any junkyard one may be good, but how long will it last?

I've gotten new fan motors from NAPA and Rock Auto.
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Good point. I didn't know this years back and paid big bucks for a whole new fan assembly. I later found out I could have bought a new motor for like $50.
 
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