15A ECU fuse keeps blowing!! Electrical guys jump in
 

The car is a 92 SI. purchased just over a month a ago as a complete shell. Swaped in motor like 2 weeks ago. Car ran fine for 1.5 weeks then i was driving...car missed a couple of times and shut off. had it towed...check under hood fuse box, noticed 15A ecu fuse is fried..I replaced fuse, drove not even 100 Feet and the car shut off again. Sure enough it was the fuse again. Handed the problem over to my friend who's experienced with electrical...long story short after he did some investigation into it..He ran a new wire directly back to the main relay...incase the wire was pinched or something.

We thought that would be the end to it as the car drove fine for half an hour..then shuts off. Sure enough i check the fuse..it's fried. What now?? I hate electrical problems. Long and hard to fix. Thanks in advance.

Check for shorts at the ecu itself. I'd check over every wire at the ecu harness to make sure none of them have wire that is exposed.

Replace ECU with test one from another car. See if that fixes problem, if not, get your wiring diagrams and start tracing!

what fuse is this?

Re: 15A ECU fuse keeps blowing!! Electrical guys jump in
 

c'mon c-pos, get it together.

whoops.

well i'd print of the wiring diagram and start tracing those wires. its rubbing through somewhere. Or try swapping ecu's (if thats easier for you)

haha i had that exact same fuse go on me, its because my elongated O2 sensor got caght in the driveshaft and ripped it to shreds lol
wasnt so funny at the time

The top of my o2 sensor presses right against my steering rack because of my header. I don't think any of the wires are phucked though...

Already did that before posting...ofcourse it didn't work. Also my directly ran a new wire from the fuse all the way to the main relay just like it does on the harness...did not solve problem. Ofcourse we did that to see whether or not the wire was being pinched somewhere...but no go. Any other suggestions before the dash is ripped out to see what's going on?

why would you rip the dash out?
Before going all crazy here, check the wires at the ecu harness for shorts. I'd really check the power/ground wires, get an ecu pinout and start with that.

If there is a pinched ground somewhere, that might trip your fuse right?
Try 2 wire from constant, + and - see what happens?

Edit: Sorry, pretty much what Zeeman just said, wasn't it? LOL

Got ya Z...will look into that. Had to have map sensor wired into ecu pin out when motor was swapped in..i'll recheck those wires and start from there on the ecu harness...I told my friend this..but he argues and says That there's no continuity or connectivity between that fuse and the ECU..which is current when you refer to the wiring schematics of the car. He's saying there's a prob on that circuit...then you start with that circuit.

The circuit goes from the fuse back to the main relay. He's saying the ecu has nothing to do with it because when you turn you key...the main relay activates the ecu and once again..there's no connectivity between the fuse and ecu..All the engine grounds seem to be fine.. I've argued with him about other grounds, like for sensors and what...but he's saying that they wouldn't affect that circuit and pop the fuse...they'd throw a code for that specific sensor. Will keep you posted.

i was more referring to the power/ground wires of the ecu, there are a bunch of them....this is where a pinout will come in handy.

it ended up being that the o2 wires were grouding out on the steering rack. Had the o2 relocated to the side of the header at the exhaust shop.

lol...oh man.
Its good that you posted the results though.

:rolleyes:

shoulda listened to the k-man

u bet, im always flippin ' right :D

lol...i should of...it's my own damn fault...all of that wasted time:)