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Burnt Ecm Harness


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  #1  
Old  May 4th, 2009, 12:13 AM
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Burnt Ecm Harness

My 1991 silverado just quit one day, hasn't started since. Won't spark. the plug that goes into the module on the distributor doesn't get any signal from the ecm. so i started looking at the harness and found a bunch of ends that were burnt(where the wires are spliced in the harness). I am in the process of replacing all of the splicings, but I have no idea what would cause the wires to burn up any way. The wires that were burnt up the worst was: the tan/black stripe(multiple splices on this wire); and one under the dash that goes from one red (on the side closest to the ecm)to red(or pink can't tell) and white
Someone mentioned a switch of some type in the altenator, but I'm not sure about that

  #2  
Old  May 4th, 2009, 9:35 PM
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if those wires were burnt up i would have the ecm looked at buy a dealer you dont want to get it back together and burn them up again also the tan/w/ black stripe runs to your distributor so make sure that is alright and check your ignition and pickup coils

  #3  
Old  May 5th, 2009, 5:43 PM
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see if you can trace the burnt wires to a pinch\chaff point. If they are only burnt at the splice, there could have been a bad connection\corrosion at one point in time, and just by normal use, caused it to get hot, then eventually fail

  #4  
Old  May 5th, 2009, 11:22 PM
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First off thanks for the suggestions. The ignition is good, and i replaced the ignition module and put in a computer lying around that i know is good, and i had a new msd coil and distributor that i had bought a while ago, so i put those in, so the coil and pick-up coil are good. I pulled the entire harness out and the only problems were just like maybe 10 places where it was spliced that were burnt up.
I thought about the "switch" in the altenator that i mentioned before, and am wondering if maybe the altenator started pumping over 14 volts and overloaded the connectors. Let me know what you think about that, in the meantime I'm going to have the altenator tested at the parts store tomorrow

  #5  
Old  May 5th, 2009, 11:29 PM
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got any more 350 computers lying around?

  #6  
Old  May 7th, 2009, 5:56 AM
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nope, just the original and my one extra

  #7  
Old  May 7th, 2009, 11:26 PM
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Well, my altenator theory was proved wrong. And everything else looks good as far as i can tell, so tonight I'm gonna try to get everything put back together and start testing wires again


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