starting problem
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starting problem
trouble starting 1990 F150, six cyl, when hot. small jumper wire off of negative battery cable gets so hot it's melts. replaced negative cable, cleaned and retightened all battery and starter connections. when engine is cool truck will start fine. appreciate any advice.
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From: Virginia
What exactly is the problem? Here are some examples:
Doesn't crank at all, maybe a click is heard.
Cranks very slowly and then stops cranking and starts clicking.
Cranks over, but has a rump-rump rythmn like it's hanging up or something.
Cranks over normally, but will not fire
Cranks over normally, and will eventually catch and run.
If you need to, go out and try it again, and really listen to what it's doing.
Doesn't crank at all, maybe a click is heard.
Cranks very slowly and then stops cranking and starts clicking.
Cranks over, but has a rump-rump rythmn like it's hanging up or something.
Cranks over normally, but will not fire
Cranks over normally, and will eventually catch and run.
If you need to, go out and try it again, and really listen to what it's doing.
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From: South Dakota
Also if when the motor has warmed up and it sounds like it is struggling to turn over this can be a sign of a couple of things.
1. Timing is advanced to far.
2. Starter motor is weak, hence the huge draw on the cables.
1. Timing is advanced to far.
2. Starter motor is weak, hence the huge draw on the cables.
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After it has been running for a while and I shut it off, if I try and start it again right away I get a noise like the starter is trying to turn it over once, very slowly. It almost seems like the starter gives one little umph and then stops. Then the wires get hot. If I try it several more times the jumper wire off the negative cable will actually start to smoke. The starter does not even come close to turning the engine over when this happens. I hear some clicking when I turn the key, but am not sure that it is coming from the relay, almost sounds like its coming from the drivers side, up by the firewall. After I let it cool down, sometimes only a matter of minutes ( sometimes longer depending on how hot it is outside and how long it has been driven), it will start right up.
Hope this helps narrow it down.
Hope this helps narrow it down.
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From: Virginia
I don't understand why the little wire melts. Is this an aux ground to the sheetmetal of the truck? If so, it sounds like the large ground cable is not doing it's job, so the current is trying to run through the little ground wire instead of the large ground wire.
But you said you replaced the ground cable and cleaned all the connections. What is the engine end of the ground cable connected to? Can this be moved to another bolt somewhere?
Also, you do not have an exhaust leak around the exhaust manifold or downfall pipe do you? Hot exhaust puffing on the starter can cause it to overheat.
I am not sure what your problem is, but the melting ground wire is trying to tell us something.
But you said you replaced the ground cable and cleaned all the connections. What is the engine end of the ground cable connected to? Can this be moved to another bolt somewhere?
Also, you do not have an exhaust leak around the exhaust manifold or downfall pipe do you? Hot exhaust puffing on the starter can cause it to overheat.
I am not sure what your problem is, but the melting ground wire is trying to tell us something.
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From: Alaska
I have, many times, seen starting motors that have become "heat sensitive", They will work when cold and fail to work until they cool off a bit.
The melted wire indicates that the wire is carring more current than it can handle due to a poor connection, a bad wire or the starter is faulty and is drawing too much current.
The melted wire indicates that the wire is carring more current than it can handle due to a poor connection, a bad wire or the starter is faulty and is drawing too much current.
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Found exhaust leak at end of tube that comes down from back of engine where it fits onto exhaust pipe. Replaced it and check valve also.
Reinspected, cleaned and tightened connections on battery, solienod and starter.
Problem persists.
Negative cable is grounded at mounting bolt on starter. Is there a better place?
The little wire is an aux grd and does go to sheet metal.
If the starter motor is "heat sensitive" and I took it out and had it tested I would think it would test OK (it would be cool) and they would say that was not the problem. Any other way to confirm this?
Appreciate your comments and ideas.
Reinspected, cleaned and tightened connections on battery, solienod and starter.
Problem persists.
Negative cable is grounded at mounting bolt on starter. Is there a better place?
The little wire is an aux grd and does go to sheet metal.
If the starter motor is "heat sensitive" and I took it out and had it tested I would think it would test OK (it would be cool) and they would say that was not the problem. Any other way to confirm this?
Appreciate your comments and ideas.
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From: Central Virginia
I agree with Franklin2 and FSC, the small ground wire getting hot indicates that something is amiss with the large negative battery cable. I would suggest replacing the negitive cable. The problem may be the starter. But, its a whole lot easier to replace the cable than the starter. And if it turns out to be the starter, you have not wasted too much on the cable. But it would be a shame to buy a starter just to find out it was the cable.
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From: South Dakota
Typically when they go 'heat' sensitive this means the brushes are going bad. When they load test the starter it will draw more current than normal. It might fall inside the 'normal' range but on the high side. Starters are fairly cheap and relatively easy to replace. I would opt for one making sure I had real good cables of at least 2 gauge or thicker. Putting the ground cable direct to the starter is fine, BUT you can lose ground to other areas like firewall(interior items) rad support(headlights, horn) so you should have a ground wire going from the firewall to the block or ground clamp on the battery. Same for the rad support, run at least a 10 gauge wire from the ground clamp to the rad support.
Even with running the ground cable to the block as normal, it is a good idea to run grounds to the firewall and rad support.
Even with running the ground cable to the block as normal, it is a good idea to run grounds to the firewall and rad support.
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I had the same problem with an '80's E-150...ground the motor to the chassis.You are experiencing a "high resistive ground" problem. In other words the battery and related circuits are not experiencing a solid, common ground through the frame, motor, chassis, etc. Your small aux. neg. cable is trying to carry the full load of the starter through a much smaller size wire required to carry the load. It's much like trying to start a dead battery with some of those cheap jumper cables....they get hot enough to melt the covering on them! Ground that baby every where you can with larger size cables, improving the current flow, and you should see a big improvement.
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From: Central Virginia
Bulldog Bubba brings up a good point about the importance of the ground system. Consider the fact that electrical current flows from negative to positive. For example, when you start your truck, the current actually flows out of the battery’s negative terminal, down the “ground” cable to the starter housing, up the starter’s cable, through the start relay, through the positive battery cable, and into the positive battery terminal.
It is accurate that any resistance anywhere is a series circuit will limit the current and dissipate energy in the form of heat. But, many mechanics seem to dismiss the importance of good solid ground cables.
It is accurate that any resistance anywhere is a series circuit will limit the current and dissipate energy in the form of heat. But, many mechanics seem to dismiss the importance of good solid ground cables.
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dominick2006
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Oct 31, 2015 02:01 PM