Need help with no-start, reverse polarity
#1
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Need help with no-start, reverse polarity
1989, Comanche, 4.0, BA 5-speed
I was in the process of selling this Comanche and the battery had gone dead. The potential buyer was going to help me jump-start the truck and when I told him to connect the cables to the dead battery, he reversed the polarity. Big spark, now nothing. I sent him on his way and pushed the truck back into the garage.
I need step-by-step help on how to go about diagnosing and solving the problem so I can get this truck running again.
I have a multimeter and I'm not afraid to use it.
Battery is fully charged now, so let me know what to do.
I was in the process of selling this Comanche and the battery had gone dead. The potential buyer was going to help me jump-start the truck and when I told him to connect the cables to the dead battery, he reversed the polarity. Big spark, now nothing. I sent him on his way and pushed the truck back into the garage.
I need step-by-step help on how to go about diagnosing and solving the problem so I can get this truck running again.
I have a multimeter and I'm not afraid to use it.
Battery is fully charged now, so let me know what to do.
#2
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Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
Look at the fusible links over by the starter relay on the passenger side inner fender. One or more is likely burned.
#4
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Year: 1990
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Not exclusively.
#5
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Gotcha. I'm gonna take a picture and post. Maybe you'll tell me what you see?
If they are burned, is it a simple matter to replace, repair?
If they are burned, is it a simple matter to replace, repair?
#6
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Replace the burned one(s)
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#8
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OK. After examining the fusible links, I couldn't see any that were visibly burned.
I looked at where they were connected as in the picture above.
Where do I go from here?
I looked at where they were connected as in the picture above.
Where do I go from here?
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The fact that I'm getting nothing in the way of current tells me the obvious: I have broken current from the battery. I would suspect the fusible links, but not sure how to tell damage other than by visuals. No obvious scorching or other burn-like characteristics. I see no "main" fuse and all the other fuses are visibly good.
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Year: 1997
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The fact that I'm getting nothing in the way of current tells me the obvious: I have broken current from the battery. I would suspect the fusible links, but not sure how to tell damage other than by visuals. No obvious scorching or other burn-like characteristics. I see no "main" fuse and all the other fuses are visibly good.
Last edited by fb97xj1; 05-25-2017 at 11:03 PM.
#14
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I think I found my culprit. One of the fusible links feels like it has no wire in it (easily bent and stretched). I plan on replacing the relay as well. Has anyone found these cheaper than $26-$30? Seems high for a relay.
#15
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Year: 1990
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You found it. Relay may be fine...