ECU running hot??

[Ed]

Hello,

I was wondering.. How hot should an EFI ECU run?

ive got mine mounted in my glove box and it becomes quite warm... is this normal?

Cheers

Ed

[craiga]

Hi Ed,

Most electronic components are rated up to 60 Deg C, quite hot to touch.

Is your ECU mounted flat against the body? If not maybe this and some heat transfer compound should lower the temperature. Many cars had ECU's either under the seat (but mounted flat against the floor for heat transfer) or behind a kick panel, but again, screwed to the body.

Find someone with a infrared temperature gun and measure the actual temperature, it may be less than you think, at the very least it will give you peace of mind.

Cheers,

Craig.

[Ed]

Hi Craig,

thanks for that info, I have mounted it using all factory mounts (VN V8) and screwed into a metal glove box compartment.

its not reaching 60 degrees (guessing) as i can still touch it and not get scorched.

when i open the glove box it feels a little toasty however the glove box is open backed and well ventilated.

just checking to see this was "normal"

im actually chsing down and electrical "leak" which discharges the battery unless isolated.  Im concerned as some spare circuits i have are reading around 0.15V directly off the fuse panel while IGN is oFF and battery is attached..

Cheers

Ed

[craiga]

Hi Ed,

I have a small tool that uses a coil attached to a needle on a guage. The coil picks up any current flowing in the wire using a similar principle to a transformer. This tool is designed to chase exactly these issues, it will help you to isolate the wire(s) where the current is still flowing after the car is powered off. You are more than welcome to borrow it, i'll be up at the shed tomorrow night if you want to pick it up. Call first though to confirm.

Some later ECU's with learning capabililties use a volatile memory so the ECU will draw a small current with the car turned off so this information is retained.

Cheers,

Craig.

[Ed]

much appreciated Craig, sounds like a handy tool.

I'll see you at the shed in that case

Cheers

Ed

[Ed]

Found my electrical leak using a very simple method...

connected a test lamp between battery post negative and earth.

If there is current draw the lamp will light up.

I systematically withdrew each fuse until the light went out.. of course i took them all out and the light was still on.

so the problem was.....

 the alternator voltage sense lead was hooked up to a 12V Constant power source, which meant it drained the battery.

A simple swap to switched power source and problem solved.

Cheers

Ed