I've got a 1996 accord wagon. The radiator fan is behaving oddly. It only comes on 1) when the A/C is turned on and 2) when the car is off. (It doesn't stay running, it runs until the engine is cool, then shuts off.) I noticed that the fan wasn't working with the A/C off because the temperature gauge started rising while I sat in traffic.

I've recently replaced the fan motor. It failed a few weeks ago.

Any ideas why it's behaving this way? I would think some temp sensor but then why does it come on when the car is turned off? Weird...

Cheers

Jeff

Sounds normal to me. When the engine is running, there is sufficient circulation through the radiator to keep the temp down. The switch is down at the bottom of the radiator.

Agreed - the fan behavior is normal. Happy driving.

Hmm.. Then there is something else going on. I will be sititng in traffic, and the temp gauge starts rising. I can pop it into neutral, rev the engine up to about 2k RPMs for a few seconds, and the temp gauge goes right back down. It's like the coolant isn't circulating correctly. I'm planning to replace the thermostat tomorrow, hoping that it might be the culprit.

Thoughts?

Thanks,
Jeff

Maybe. Or maybe it's the water pump (seems unlikely, unless it's leaking).

Thermostat isn't going to be the reason (I don't think).

Has the coolant been drained (partly or completely) lately? If so, was the cooling system bled afterwards?

Well, I replaced the thermostat, and the overheating problem went away. Before, the fan would not kick on and the temp gauge would keep rising. After replacing it, the fan now kicks on, the temp stays "normal" and the needle doesn't fluctuate. The thermostat seemed awfully new but quite visibly different than the Honda one I installed. I wonder if it was not allowing any coolant to circulate unless the engine (and water pump) was spinning faster than idle speed. Can coolant flow open a thermostat? It was not stuck like ones I've replaced in the past, it moved smoothly.

I also made sure to bleed the system so there was no bubbles in the coolant.

Cheers