ECU power question?

[colorado80439]

Looking for suggestions, we are chassis wiring and do not have the engine wiring harness yet. (E38 ecu) we're installing a battery disconnect next to the battery controlled from a toggle switch at the instrument panel. I'm questioning whether we need to have constant power to the ECU if I will be using the battery disconnect frequently. IE bypassing the battery disconnect to power the ECU

Thanks!!

[dhutton]

Yes you do or you will lose all your fuel trims etc every time you remove power.

Don

[colorado80439]

Originally Posted by dhutton

Yes you do or you will lose all your fuel trims etc every time you remove power.

Don

Thanks Don, you're the man.

[65 Drop Top]

I believe you can use a small fused jumper wire to keep the ecu memory.

[colorado80439]

Originally Posted by 65 Drop Top

I believe you can use a small fused jumper wire to keep the ecu memory.

OH! I like that idea, I'll research that for sure
Thanks so much!!

[572Camaro]

American Autowire sells a “lifeline” which is a small circuit breaker that can bypass your main disconnect switch. If you trip the breaker, it auto resets.

I don’t know anything about your ECU but most aftermarket EFI companies want you to run power and ground directly to the battery.
I run FAST and they demand it due to electrical noise.