Fuse Keeps Blowing...Need Some Help

One of the 2 ECM fuses blew twice today on my brother's '93 S10 (4.3l V-6 w/4L60e). The truck does have around 230k miles on it.

Something is obviously causing some kind of extra draw....just started doing it too.

What should I be checking for? Any chance the computer is finally going bad? I don't think the CE light was on during all this.

Thanks.

 

FUSES

Hey Gsxman,You are going to have to get some sort of wiring diagram for that truck to see whats on that circit that might be blowing the fuse.. First i would check the injector wires on top of the thottle body if they get pinched it will pop the ecm fuse..let me know what you find .

 

fuses

scott, remember that a fuse is like a safety device on your car. when a fuse blows it means its done its job, which is protecting your cars wiring system from burning up if there is an abnormal surge of power. install a new fuse, with the engine off and the key on carefully check the wiring in your engine compartment. check your wire looms to the fuel injectors and the ecm itself if its located under the hood. the ecm is placed in different places in different years in these vehicles. also check the wiring by your starter. our shop once had a 1995 gmc gimmy blow ecm fuses because the fuel pump wiring inside the gas tank was shorted out. these kinds of problems can sometimes take pros days to find the problem, so dont get discouraged if you cant find it right away. good luck

 

Quickest way through would be to Unplug the ecm, replace the fuse. turn on the ignition and see if it lives. if not you have a pinch or other isuue going to the computer if it lives shut off car and unplug likely items such as the injector harness, fuel pump (if you can), or of the like. Turn on the car with those unplugged. If the fuse is still good, you have narrowwed the search considerably. Then shut the car off and put back one thing at a time until the fuse blowes. not as easy as it sounds but probably the only way of finding this short to ground(or close) within a reaonable time frame. Good luck.

 

I should add, that the fuse took about 30 minutes or so, in between the 1st and 2nd fuse blowing. It wasn't one right after another.

I'll look at the injector wiring tomorrow. If I remember correctly, there may have been 'issues' in the past. I think he said there was some light fire damage to the connectors and wires.

For the most part, the truck had been running pretty reliably - up until this.

 

If you have some fire damaged harnesses It may be better to "shot gun" some things. like replacing sections or harness with one from a salvage yard.

That will be one of those things were you'll probably have to get dirty, throw logic to the side and just start inspecting every Inch of harness. :ball:

 

I took a better look at the injector wiring area...definitely got 'slightly scorched' at some time in the past. I didn't see any totally bare wires...but it got pretty 'thin' in some areas. I got out the electrical tape for now. Eventually, I'll just pick up a good section at the junkyard and properly fix it.

So far...so good.:grin:

 

:TU: