I have a 90' RS with a 305 TBI motor. It has one cooling fan. Does the fan have 2 speeds? One speed for cooling w/o A/C on and a second speed when the A/C is on? If it is a 2 speen fan, is there a fuse that controls that controls the low speed?

Reason why I was asking is I think my fan is not working when the A/C is off but works when the A/C is on. I have to double check to make sure this is the case. The car ran for about 10 minutes and the temp shot up to 260 degrees. Don't know if the gauge is accurate but the radiator cap did not feel hot to the touch which leads me to believe its not accurate.

I was in the process of flushing out the system. I empty it out and refilled it . I suspect a possible air pocket which caused the temp to spike but can't figure out the fan problem.

 

one speed, on

temperature fan switch controlled, on @ 238°

a/c also turns fan on

gauges can get a certain amount of inaccuracy after 19-29 years, they aren't swiss made. though, the sending unit can go bad as well as the wiring so, it is not always just a 'crappy gauge' causing the problem.

 

It had air air pocket. Problem solved fan works. Problem was I was doing this at night and didn't fill cooling system all the way up (Due to I couldn't see what I was doing). The Temp spike really fast and I shut it off. Being it was dark I couldn't see if the fan came on or not. I think the temp spiked so fast it didn't have a chance to even come on.