A12 fan control

travis1976 · Post by **travis1976** » Sun May 23, 2010 8:59 pm

Was using the ecu to control the fan. One day heard the relay going crazy under the dash. I unpluged it and found that where the ecu was going to ground the relay the relay was sending a 12 volt out. I'm pretty sure it fried that part of the ecu. I purchased a new relay from my tuner that he uses and my ecu isn't sending anything out A12 anymore. I have tried to trace it through the ecu, does someone have a pic showing the part of the ecu? Or maybe describe what I should be looking for? thanks

rudebwoy · Post by **rudebwoy** » Mon May 24, 2010 2:49 am

same problem different situation, how to repair that.

Post by **Hondata** » Mon May 24, 2010 9:06 am

The fan output uses QM3. If you're electronically skilled then you can try replacing it from another ECU.

travis1976 · Post by **travis1976** » Wed May 26, 2010 5:42 am

Thank you for that info, that was exactly what I was asking. But....

I checked over a few things. Turns out, all relays work that way, letting current through until closed with power. At least every electronic device I could find did. Checked it and A12 was working fine. I could turn it off and on by changing the temp operation. So I hooked up a relay and it was working fine. Went and finished hooking everything up and then went to turn it on and now nothing. ECU doesn't put out anything. Can anyone help? I really need my radiator fan.

Post by **Spunkster** » Wed May 26, 2010 9:44 am

You should be using a thermo switch that activates the fan. The ECU control is a backup and should not be yoru sole source for operating the fan.

travis1976 · Post by **travis1976** » Wed May 26, 2010 4:43 pm

Could you help me figure it out anyway?