95 Taurus 3.0 overheating - Relay or fan?

My 95 Taurus with 3.0 started overheating horribly leaving the race track last weekend. Runs cool at highway speeds, but wants to overheat when bumper-to-bumper or sitting still. Heard fan kick on once after I gave it a
little push (with the key off - I know, not a smart move), but it generally does not kick on. Now - how do I determin if it's the fan motor, or the relay? Fan will move when pushed by hand, but not continually spin freely. How do I test to find out which is bad? It does need a coolant flush - it's been 2 years since I last did it.
--
-Barry

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Lead Driver wrote:

If you have a volt meter, you can measure the voltage at the fan terminals. If you have 12 volts and it does not spin, its the fan. If you don't have 12 volts (when hot of course), its the CCRM relay module or a computer issue. You need to see where there is voltage and where there is not.
Bob
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BOB URZ wrote:

Bob is right on the money here. Right on the money. That advice is exactly right. I know this for a fact because even though it's not exactly the same thing it's the same electrical theory. I worked on HVAC before. When fixing residential and commercial heaters an HVAC technician needs to do precisely that. He needs to hold a volt meter to the connectors to see where there is voltage and where there isn't. If there is voltage where and when it should be and vice versa. It's all about trouble shooting and rulling out possibilities.
East-
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Okay - first off, thanks for the advice. Now, more of my ignorance.
I got my car heated up today, and pulled out a voltmeter. First connection I checked got 14 volts, so I plugged it in. Viola! The fan worked! Yay, right? No - now I can't figure out why it's working again! I left the car running - it would heat up, then the fan would kick in, just like it's supossed to. Now I want to know WHY!!
Any ideas? Loose connection? Dirt? In this picture, the lead plugs into a box (the fan relay?), which in turn plugs into the fan. This 'box' was pretty hot - but then again, considering it's location, maybe it should be expected to be hot.
http://i32.photobucket.com/albums/d39/BrocktonBarry/carfan-1.jpg
Anyhow - count myself lucky, keep an eye on the car, and go about my merry way?
I hate not having an answer as to why it works now.
Thanks again, for the advice and help, folks.
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Look close at contacts... high current corrosion.... much like battery terminals
Simple fix, plug/unplug several times, then get dielectric grease and coat contacts liberally.
If air cant get to it, wont corrode.
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