Radiator fans not working at idle only

559 Views 1 Reply 2 Participants Last post by Fibber2, Feb 28, 2020

Itmainman

Discussion Starter · Feb 27, 2020

I have a 2004 Sienna with 380K miles. While the engine is hot, I can hear the radiator fans running as I come to a stop light but as soon as I come to a complete stop the fans will go off. If I sit in a drive through or leave the van running while parked it will start to overheat. Otherwise it’s fine, I’m 100% the fans are fine and they only come on when the temperature is high. So temp sensor must be good. What would cause them to stop at idle only. Thanks

Save

1 - 2 of 2 Posts

Fibber2

· #2 · Feb 28, 2020

How's your system voltage? Does it drop below 12.5 or so when your van is at a standstill? I'm thinking a microcontroller is sensitive to low voltage. Could indicate an alternator / voltage regulator issue, or even a questionable battery.

The fan microprocessor controller is between the fans on the center radiator mount. Powering that, IIRC, is a cube relay in the fuse box next to the battery. Check inputs and outputs of these components to track down your issue.

Save

1 - 2 of 2 Posts

This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.

Top Contributors this Month