for the love of god, please help. burning up ecu's

[clovers525e]

ya, like the title says i'm burning up ecu's. i just fried my second. i think i might have enough spare parts off the first one to repair it but i need to know the problem. here is whats going on;i just got my s14 sr swap done a little while ago and it ran fine for a month if not longer until i was driving down the road and the car just dies, i smell smoke and pick up the ecu and there is smoke rolling out of the sides. i cracked it open to see and the two round tubes with wires comming out of each side that say "mo" on them where burnt up, the ones closest to the wiring harness. the wire they seemed to run off of is the power wire for the computer. i looked around the eccs relay but didnt see anything open. i dont really know how to check for shorts, which is what i'm sure i have. do i check the amp's? can i run a inline fuse so i wont burn up another ecu?like i said, this is a s14 sr with a wc ecu.

[SpeedRacer1]

It sounds like you are burning up the ECU where everyone else fries theirs. There is a good chance that some of the wiring ended up melting/rubbing/touching and powers are getting shorted.

I last saw this happen when a guys wiring for his MAFS was placed over his exhaust manifold. The wiring obviously melted quickly and shorted the ECU. But it has happened to other people in other ways.

Go over your engine harness for damage, cracks, etc.

[sylviadrift]

yeah wrap those wires up goood thats the best thing to do.

[sylviadrift]

i hate weird probs like that.

[Naloos13]

Welcome to my world..... Fried two, and then realized i could fix them. If you are good at soldering, cut the burnt trace out and solder a trace wire across, or search for a circuit board place in you area and ask them if they could do it for you. I had both mine fixed for $50 from a circuit board place.

FYI, putting a jumper wire will make your car run and drive, but somewhere on the ecu there is a fried diode that shuts your car off....i am still searching for that. For the time being i dump the clutch in 4th....Best of luck, let me know

[Naloos13]

sorry, a lil confusing. There is a fried diode somewhere that controls shutting your car off. However, since its fried your car wont turn off, unless it is replaced.

[clovers525e]

ya, i tried to fix the first one, so its completely trashed this one i left well enough alone, i used to work at a tv shop and they can fix it i'm sure. what i'd like to know though is what amp does the ecu run on? i want to run an inline fuse to that wire so it'll go before the ecu does next time.

other then that i guess i'm back to pulling the whole wiring harness back out and checking it. i'll probably have to do it late tonight before anyone notices since you cant work on cars at my appartments i think that wire that shorted out just runs to the eccs relay from the battery and then the computer....dunno. does anyone know how i could go about getting a replacement diode?

[Naloos13]

I'm not sure what amp fuse to run, i have tossed that idea around with another person w/ this problem, but the best way is to rip apart the harness and figure it out for good. Yea, my landlord doesnt like me working on my car at my apartment, so i pull it out on the public street, which is 15 ft from my parking space and do all my work there. You can get replacement diodes at tons of places, radio shack is usually pretty good. The only problem is that no one knows which diode needs to be replaced yet. There is some company that knows which one to replace and will fix your ecu for $70. But they wont tell me which one it is so i can do it myself. So i am still testing them..i will post as soon as i figure out...hopefully this weekend.

[clovers525e]

well, the good thing is i found a wire going to my whiper amp that was split, thats another problem down. i'm getting the harness out tonight and i'll look at it (at about three in the morning). i figgure if it ends up waisting any more of my time and money i'll just end up selling it and buying a volvo or a honda. on the ecu there are just thoes two little diods that are burnt up next to the wiring harness (for the power plug) that i can tell atleast. hopefully i wont find more that i cant see.

[clovers525e]

ok...its two in the morning and i'm tired and rethinking the whole volvo idea now. a s60 R would look really nice in the driveway.

i pulled all the connections off the engine and untangled the whole harness so i could pull it out when i realized, you have to take the blower motor out and the dash before that to remove the wiring harness on s14's, gggggggggggaaaaaaaaaayyyyyyyyyyyyyy, so i gave up on that idea and decided to go ahead and get my girlfriend to check the volt meter for continuinity while i plugged everything back up. i checked continuity between the power wire that shorted out on the ecu and the chassi, i think that should be right, it should only be grounded inside the ecu where its being used as power. well, i started plugging things back up, eccs relay, power steering relay and when i got to the f4 or f3 plug (which every you want to call it) the volt meter jumped to zero. i had continuity between the sensor ground and the hot wire while the ecu was pluged up and none while it was unplugged but i think that is right. anyways, so somewhere in the wiring for the f3 plug, the WHOLE rest of the dash harness and the ecu wiring clip, something is touching the body........i was going to start with the f3 wiring but then i rethought that, if there is something touching the body and i had all the grounds for the f3 unhooked, then it would have to be in the dash, probably around the steering colume, where that grounded power could be. the next logical steps i see i could take would be to figgure out which wire that runs though the f3 is the same as the eccs power wire, one, track that one wire down to find where it makes contact with the body, two, and wire in a temp wire for the eccs power hooked up to a switch with an inline fuse so i can drive it home after i get the eccs fixed. what i need to know from someone is if there eccs power has continuity with the chassi, if your ecu is exposed, its really easy, its the fat black one with the red stripe. and still, what amp to run the eccs at.

help a brotherrrr out