'89 Tempo/Topaz Fan Control Module Q

Have an A/C-equipped '89 Tempo/Topaz with an inoperative radiator fan. I jumpered the fan to the battery, it works. I jumpered the relay on the drivers side headlight, it clicks and my multimeter says it has
continuity when energized. I also tested the coolant temp sensor near the thermostat and it has continuity when the engine is hot.
According to the Haynes, that leaves the cooling fan controller behind the glove compartment. The book does not describe any testing procedure, is this one of those replace-and-hope-that-was-it kind of parts? The kind of auto repair that I hate?
Any advice is appreciated. Thanks!!
P.S. And why did Ford need such a complicated fan system, anyway? How about a relay to kick in the fan when the A/C was on, the engine was hot, or both? Seems to be a whole lot easier and cheaper to me!
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I can't even attempt to rationalize the Ford engineer's reasons for the fan controller design, but I can tell you that when you find the relay and look at the wiring harness connector you will see that it is practically melted from the current going through the fan power supply wire. The relay may still be good, but the terminal in the connector will most likely be burnt. At least that has been my experience with that particular model. I would say the design is flawed in that it doesn't hold up to the heat caused by the cooling fan current once the fan gets a little older and starts drawing a few more amps that it should. Proper diagnosis should include checking the fan current draw to make sure it is not above factory specification and perform voltage drop tests across the harness connections to make sure there is not any resistance that could cause them to heat up and melt the connector.
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Kevin Mouton
Automotive Technology Instructor
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Hmmm. I didn't see any burned connectors but then again, I wasn't looking for any. I'll double check and probably hit the junkyard for the parts, hey value priced parts for a value priced car. :)
Thanks Kevin for the info!
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