Sorry for bringing up an old thread, but I have a 1995 Integra hatch B18B1 Non-VTEC ls swap with a GSR transmission. My top left, under hood 15a fuse (ECU fuse) keeps blowing. I tried cleaning all of the connectors / plugs in the engine bay and I tried cleaning the ECU / thermostat ground. Not really sure where I am getting the short. I unplugged the main relay and tried starting it and the fuse did not blow. I have a multimeter ready to start testing for ohms, but I am not really sure where to begin. All help is greatly appreciated! Also have a red connector coming from the radiator harness not plugged into anything...

 

Try another new or known used in working condition main relay.

 

I tried a main relay that I got from a junkyard awhile back. Fuse still blew. So either both were bad main relays, or I have a wiring problem... Maybe grounding issues or a bad connection somewhere? I still have a lot to learn about wiring. Any other ideas?