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The PCM turns the fan on (or tries to) when the engine coolant temp sensor (located on the pipe line leaving the thermostat housing, pretty much obscured by the large rubber air inlet duct) thinks the coolant is above about 210 degrees. That sensor has two contacts to its connector,and if you pull that connector off of the sensor, with the engine running, the can should turn on. But there are 3 other relays involved. The relay inside the fuse/relay box close to the driver's side strut tower has the relay which is sup;posed to supply 12 volts to one side of both fan relays (these are hidden behind the air filter housing inside the fender. One of them gets one side of its coil connnected to ground, for the low speed fan to come, the other relay gets one side of its coil connected to ground to cause the high speed fan to come on. Each of these relays may have some melted contacts or melted connectors to them.
A good test of the fan is to pull the connector apart, and connect 12 volts directly across two of the wires, and across the other two wires, thus testing for both low speed fan and high speed fan motor operation The fans themselves do quit working after enough years - bad bearing, bad motor coil, etc.
With a 99 I believe, the fan should run very briefly at the time of first turning on the ignition. You may need to have the hood open to hear it or feel the air flowing. This would only be for a few seconds.
 

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Glad that you are having some success with the car, and thanks for letting us know.

If the a.c. is working and you have it on with the engine idling, the fan should be running; either immediately after you turn the a.c. on, or soon thereafter, since the coolant will get hot pretty soon.

It is possible to buy a small coolant tester, which you use by sucking coolant into the tester with its rubber 'bulb', and it will tell you either the percentage of antifreeze in the system, or the boiling temperature / freezing temperature of the coolant. Doing an ebay search for the terms "antifreeze tester" will show you what they look like. Should be done when the coolant is not hot, at least not scalding hot.
 
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