1987 s10 ecm problem
jonny.chinn
02-15-2007, 01:30 PM
my 87 s10 has a confusing problem. The ecmb fuse keeps blowing. when i take it out the starter will crank but no start, no headlights, interior lights, radio. when the fuse goes back in, all of the lights work but the starter will not crank, then the fuse blows. please help, thank you. could the ignition switch be bad or is it something else.
DelCoch
02-16-2007, 06:10 AM
Apparently you have a short in the wiring somewhere - (not with the starter). Check the wiring harnesses that run next to the engine and the transmission. Look for signs of a burnt wiring harness from engine heat or evidence of rubbing against metal.
jonny.chinn
02-16-2007, 04:48 PM
thanks for the help. i'll check out the wiring harness, also do you think that it could be the ignition switch.
DelCoch
02-16-2007, 05:24 PM
I doubt it would be the ignition switch. When a switch goes bad it doesn't usually blow fuses. I think it's bad wiring, a bad sensor or a bad component between the ignition switch and the ECM Unit, or downstream from the ECM Unit.
Does the fuse blow as soon as you hit the starter position on the ignition switch or does it take a while to blow?
The ECM fuse kept blowing on my '95 and I found the wiring harness going to the crankshaft sensor had gotten up against the engine block and melted a very small spot on the wiring harness and through it into the wires. (Not an easy one to spot) Thus, when the starter was activated the ECM Unit would send current through the wire to the crankshaft sensor, which was shorted out, thus it would blow the fuse. Sounds similar to your problem.
I would get a good supply of fuses and as you replace them, disconnect various wire connectors going to various components, one at a time, and see if the fuse still blows. When you find the fuse no longer blows your on the right track.
A word of caution - don't use a higher amp fuse than is called for - (maybe a less amperage) as in my case I was stuck along the highway and put in a higher amp fuse (all I had) and it burnt the wire in half that was shorted out and the fuse no longer blew, which made the problem harder to find.
Does the fuse blow as soon as you hit the starter position on the ignition switch or does it take a while to blow?
The ECM fuse kept blowing on my '95 and I found the wiring harness going to the crankshaft sensor had gotten up against the engine block and melted a very small spot on the wiring harness and through it into the wires. (Not an easy one to spot) Thus, when the starter was activated the ECM Unit would send current through the wire to the crankshaft sensor, which was shorted out, thus it would blow the fuse. Sounds similar to your problem.
I would get a good supply of fuses and as you replace them, disconnect various wire connectors going to various components, one at a time, and see if the fuse still blows. When you find the fuse no longer blows your on the right track.
A word of caution - don't use a higher amp fuse than is called for - (maybe a less amperage) as in my case I was stuck along the highway and put in a higher amp fuse (all I had) and it burnt the wire in half that was shorted out and the fuse no longer blew, which made the problem harder to find.
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