I have a 1995 Honda Accord EX wagon, 2.2-4cyl, AT, 242K on the clock. Over the weekend, the passenger-side radiator fan started running constantly, even with the key off (I discovered this after coming out to the car after it sat overnight, only to find the battery was dead; when I hooked up the jumper cables, the fan immediately started running). Since then I've been disconnecting the negative battery cable every time I shut the car off and plan to leave it sitting for more than 20 minutes - not an acceptable long-term solution.

I've looked through the forums and on other sites, but can't seem to find the exact problem and it's solution. Anyone experience this? Is it a bad coolant temp sensor, fan relay, or....??? Thanks for your help!

 

Check your relay for that fan. They can get stuck in the closed position.

 

Hi member, try to find answer with this site..they seem to help alot of members out with problems.

WheelBroker

http://www.automd.com/repair/honda_m12/accord_mm54/
Follow this thread ^

 

I replaced the fan relay in the underhood fuse bank (thanks rockhoundrob for the suggestion), and that took care of things.

I first tested the theory that it was the relay by simply pulling the relay out and driving the car as I normally would for a day (it was only in the 50's outside-temperature-wise, so I felt safe in running the car a bit without the benefit of the radiator fans), and presto - no more constant passenger-side fan run-on problems. The part was about $10 brand new at the local auto parts place.

 

Glad you got it fixed.

This is a test method for someone with a similar problem. One way to test a fan relay is to switch it with an identical relay nearby. If the fan had stayed on with a different relay, you would have to figure out why the relay is constantly being switched on.