Help please
 

I have a 96 RS with the 3.8L V-6. The coolant fans are not coming on for anything. The relays have been replaced. They came on the other day when I turned the ac on, now they wont at all. I pulled the thermostat on the side of the road the other day so I could make it to work, just trying to fix it now.

Way to pinpoint the relays being a possible culprit.. it could be a thermostat problem, have you had any trouble with the car overheating? When you turn the A/C on do they come on? The computer on the 3.8 is usually programmed to kick the fan on at around 200 degrees(I believe 221)

I have replaced the thermostat as well. The new one is the one I pulled out the other day. I put it back in earlier today and bled the air out. I let the car warm up to check fan operation, but they never came on. I turned the ac on after the gauge was reading almost red, but the fans would not come on. I have only had the car for two weeks, bought it really cheap, but just trying to work the bugs out. The fans will come on with direct power.

Just put a new coolant temperature sensor in and now the gauge is pegging out and the only way the fans will turn on is to unplug the sensor, guessing that is because the pcm is detecting bad sensor? Any clues why the gauge would be pegging out?

maybe you got a temp sensor for a car with "idiot" lights instead of a car with gauges? Just a possibility.

either the sensor is bad or the wiring is grounded. grounded sensor wire will show max temp. test the sensor. http://shbox.com/1/4th_gen_tech2.html#ect

Check your ground first before spending anymore time and money. First thing I always check with an elec issue and would be a quick inexpensive fix . They can virbrate loose that is why I always loc tite my grounds.