Driving with the a/c on and I noticed that it started blowing warm air then it would blow cold again after a 30 secs. or so and then repeat the process, I then noticed the temp guage at H! so I pull over and pop the hood.... cooling fan isnt moving? so i turn the a/c back on and still no fan? Took out the fan relay and plugged it back in and immediantly felt it click over, so i figured it was ok? I then drove home with the a/c off and when i opened the hood it was boiling hot at the resevoir while the temp guage was right in the center of C and H. I checked the fan by running power from the battery to the three prong plug and it worked. with the fan powered directly to the battery i then started the car and turned on the a/c.... same thing, cold for a few seconds then hot. Turned off the car and the while disconnecting the wire from the fan noticed it was quite hot (not a very high guage, but not thin either). Any help would be really appreciated.

 

Sound's like the relay is bad.I would get a new 1.Then if the problem persist i would look at the temp sensor.If it has 2 wich I think it does.

 

Temp sensor.... so when you say "two" does that mean that one tells the ecu to open the relay and the other tells the ecu to open the thermostat? and the temp sensors should be screwed into the block somewhere , correct?

 

They are screwed into the block or intake .1 is for the gauge or light and the other is for the computer wich tell's the fan when to turn on.

 

new temp sensor, same thing. tested relay in engine fuse panel and two on the fender wall, all tested good. hot wired fan to battery, spins. tested temp guage by grounding wire off of the sensor, good. temp gauge sensor works. fuse, good. conclusion.... mild to severe headache with occasional violent outbursts! ECU? SHORT? WTF? another thing is when i had the fan hotwired and the car started the a/c still did the same thing blowing cold then hot etc.

 

how hot does it get on the gauge before you shut it off?

 

over or about half way or until i see the resevoir start to boil...

 

That fan should kick on @ 190 - 220 degrees.If the anti-freez mixture is not at least 50 -50 it may boil before the fan comes on.I would make sure the mixture is correct and try to get the tempature by runing it with the radiator cap off.Also has the cooling system been worked on recently.If so you might have a air pocket.

 

Trust me its hot... and no, the cooling system has not been worked on. as i said b4 everything was fine driving along then noticed the air getting warm than cold again, then noticed the temp guage maxed out! so i pull over pop the hood and i have no fan action.... and now im here.... the a/c, cooling fan problem both happened at the same time.

 

Then there is a wiring problem.I would trace and test all the wire's from the fan to the temp sensor to the relay to the computer.