alright, i have a 95 accord ex auto..when the car is at idle it will start to overheat and the fans wont switch on, but once i turn on the ac the fans will come on and the temp will go back down..and once i start driving again, the temp will go back to normal also..it seemed that the coolant was a little low also..Im definitely going to buy a new radiator but i dont think that will solve the problem with the fans not coming on..any help would be appreciated..Ive searched around and find a lot of different answers..I thought maybe it has happened to someone on here..thanks a lot guys!!

 

More than likely Coolant switch a (thermo a) is not working. This switch is located on the t stat housing (green plug) where the LOWER hose connects. Around 196* the switch should close sending the ground signal to the fan relays-causing the fans to come on. If you have a volt meter you can test the switch.

Since turning on the ac makes BOTH come on this is where I would start.

 

Thanks a lot!! I will give it a shot this weekend when im back home..I appreciate the help..If anyone else has any other input, please share

 

Make sure you bleed out any air from the cooling system. There's a little bleed screw on the T-stat housing. Air pockets trapped in there might cause the problem.

Unplug that switch Poorman mentioned, and bend a paperclip to short between the 2 wires. Key ON, that should make both fans run. If it DOES, then you've just proven that everything except the thermo-switch-A is good.

 

Thanks a lot for the instructions! Looking frwd to trying it this weekend..I'll let you know how it goes

 

IIRC, there are two fan switches. One on by the T stat housing and the other further toward the rear of the engine. My 95 Accord had much the same problem you describe and it was the rear switch that was not working until the temp gauge was close to the red when idling. I picked one up at a wrecking yard for $5.00.