Eric M.
1/2 ton status
1991 Burb, V2500, 350, L480E, all stock.
Went to start, cranked, but would not turn over.
Found ECMB fuse was blown (10A), replaced w/ 10A.
Burb started fine, let it run in driveway, about 10 min. later it died, fuse blew again.
Installed 15 amp fuse, let truck run in driveway for 2 hours, no problems.
Went to start this AM and fuse was blown again. Installed another 15A fuse.
Truck started and ran fine.
I'm assuming this is an intermittent elect. short in one of the components on the ECMB circuit and will be next to impossible to chase down as it seems to happen for a very short time (long enough to blow a fuse) and them goes back to working correctly.
Before I pull out the shop manual and elect. schematic and spend the better part of the next week trying to diagnose this problem, I thought I'd ask if anyone has run into this before.
Thanks,
Eric M.
THE FIX There was a short in the ECMB wire. It would only short for a split second, enough to blow the fuse, then go back to working fine. Made it difficult to track. I tried changing every component on the circuit, then drive and wait. I'd get a week to a month and the fuse would blow. Stick a new fuse in and I was good for at least another week. I bought a box of 30 fuses and figured sooner or later it would short and stay shorted. It did finally. I pulled everything off the circuit and it still shorted. I then cut the wire on the back side of the fuse panel and no more short. I ran a new wire from there to all the components and the truck started. Just for kicks, I reconnected the cut wire, and it did blow the fuse again.
I have no idea where the short is and am not going to unwrap a mile of spagetti under my hood to find it. But, I will say, there is no obvious place where it could be grounded out. The wiring is all stock and in very good condition. It's all very odd, but as long as I don't have to carry around a box of 10 amp fuses anymore, I'm happy.
Eric M.
Went to start, cranked, but would not turn over.
Found ECMB fuse was blown (10A), replaced w/ 10A.
Burb started fine, let it run in driveway, about 10 min. later it died, fuse blew again.
Installed 15 amp fuse, let truck run in driveway for 2 hours, no problems.
Went to start this AM and fuse was blown again. Installed another 15A fuse.
Truck started and ran fine.
I'm assuming this is an intermittent elect. short in one of the components on the ECMB circuit and will be next to impossible to chase down as it seems to happen for a very short time (long enough to blow a fuse) and them goes back to working correctly.
Before I pull out the shop manual and elect. schematic and spend the better part of the next week trying to diagnose this problem, I thought I'd ask if anyone has run into this before.
Thanks,
Eric M.
THE FIX There was a short in the ECMB wire. It would only short for a split second, enough to blow the fuse, then go back to working fine. Made it difficult to track. I tried changing every component on the circuit, then drive and wait. I'd get a week to a month and the fuse would blow. Stick a new fuse in and I was good for at least another week. I bought a box of 30 fuses and figured sooner or later it would short and stay shorted. It did finally. I pulled everything off the circuit and it still shorted. I then cut the wire on the back side of the fuse panel and no more short. I ran a new wire from there to all the components and the truck started. Just for kicks, I reconnected the cut wire, and it did blow the fuse again.
I have no idea where the short is and am not going to unwrap a mile of spagetti under my hood to find it. But, I will say, there is no obvious place where it could be grounded out. The wiring is all stock and in very good condition. It's all very odd, but as long as I don't have to carry around a box of 10 amp fuses anymore, I'm happy.
Eric M.
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