Hondata

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

same problem different situation, how to repair that.

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

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.

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.

Could you help me figure it out anyway?