Have a 99si. Aem cam gears,short ram and fuel rail. Greedy evo exh. and dc headers. When the temp is about 85 or higher and my ac on. My car runs hotter than normal. If I turn the a/c off or drive, the temp returns back to normal. My radiator fan does come on when the temp is on the rise. I have replaced the coolant and the thermostat. Any info on this.

 

you only have one header......

 

how overheated does it get? if its just a little, thats normal cuz the ac adds more strain tryin to produce cold air making shit hotter. if you're getting into the red, then you gotta problem.

 

Is your fan coming on???

The AC should have little bearing on it, as it uses it's own "radiator". It does have some bearing as it uses power from the engine to run the pump, but not much more than an alternator.

I would suggest seeing if your cooling fan(the one for the radiator) is coming on or not. If it's not, you may need a new thermo-switch. This is the switch that tells the ECU how hot the engine is and when to turn the fan on. Most of the time they are located in the thermostat housing. Someone may be able to direct you better than I can though.