Starter problem...appears shorted to gnd
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Starter problem...appears shorted to gnd
1986 F-150 w/ 302 & EFI
A few days ago, had problem starting with engine hot. If let it cool 1hr, started OK. Acted like low charge on battery when hot. I checked battery terminal and noticed that positive terminal too hot to touch, but negative cool.
Yesterday, It wouldn't start at all...cold or hot. With ignition on, positive terminal very hot. If I tried to engage starter, all lights on dash & radio went out. If I turned on headlights, dash lights & radio cut off.
I disconnected wire connected to starter. Using ohm meter, I measured 0.7 Ohms to gnd at starter terminal. Radio, headlights, work OK with starter wire disconnected, but dash lights don't turn on anymore when ignition is on.
I looked through some other messages and found some starter heat problems, but didn't see anyone describing this same problem.
What do you think? Is it a starter failure?
Thanks, Steve
A few days ago, had problem starting with engine hot. If let it cool 1hr, started OK. Acted like low charge on battery when hot. I checked battery terminal and noticed that positive terminal too hot to touch, but negative cool.
Yesterday, It wouldn't start at all...cold or hot. With ignition on, positive terminal very hot. If I tried to engage starter, all lights on dash & radio went out. If I turned on headlights, dash lights & radio cut off.
I disconnected wire connected to starter. Using ohm meter, I measured 0.7 Ohms to gnd at starter terminal. Radio, headlights, work OK with starter wire disconnected, but dash lights don't turn on anymore when ignition is on.
I looked through some other messages and found some starter heat problems, but didn't see anyone describing this same problem.
What do you think? Is it a starter failure?
Thanks, Steve
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Joined: Jan 2002
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sounds like a bad ground going down there, it is not completing the circuit. on my 88' i had to clean the connections a few times. try taking a set of jumper cables and using the ground side only connct one to the batt ground then the other to the starter body and see how things work
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Joined: Nov 2003
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From: Central Virginia
You have the symptoms of a poor connection between the positive battery terminal and the battery cable. I would suggest cleaning the battery post and replacing the battery cable. It is likely that the cable itself is faulty.
Heat is produced in an electrical circuit when current flows through a resistance. The battery, start relay, and starter are in a series circuit. There is the exact same amount of current flowing through both of the battery terminals, the relay, starter, and the cables. In a good connection, there is very little resistance and therefore very little heat. If one battery terminal is getting hot and the other is not, it is very likely that the fault is the hot battery/cable connection or the cable itself.
Your starter circuit flows a lot of current, about 200 AMPS. It doesn't take much resistance to create a lot of heat with 200 AMPS flowing through it.
Good Luck: Let us know if a new cable and a good cleaning fixes the problem.
Heat is produced in an electrical circuit when current flows through a resistance. The battery, start relay, and starter are in a series circuit. There is the exact same amount of current flowing through both of the battery terminals, the relay, starter, and the cables. In a good connection, there is very little resistance and therefore very little heat. If one battery terminal is getting hot and the other is not, it is very likely that the fault is the hot battery/cable connection or the cable itself.
Your starter circuit flows a lot of current, about 200 AMPS. It doesn't take much resistance to create a lot of heat with 200 AMPS flowing through it.
Good Luck: Let us know if a new cable and a good cleaning fixes the problem.
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I believe you are all correct about my cables/connections. I tried the suggestion of using a battery jumper cable today and it cranked.
Thanks for the help. I'll get some new cables and let you know how it works out.
Regards, Steve
Thanks for the help. I'll get some new cables and let you know how it works out.
Regards, Steve
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