Electrical Issue - Weak Cranking, Flickering

[mistaake]

Every time I start the truck, the lights get very dim, it cranks really weak, as if the battery is almost dead. Whether it's the first start in the morning, or it's been driving all day and is still hot, doesn't make a difference.

But the battery is only a few months old and tests good and it's not discharged. Battery connections are tight and look clean.

My other issue, is when the truck is running, everything (dash lights, headlights, etc) flickers constantly, just a little bit, but it is noticeable.

Thanks for any input. It's been issue after issue with this truck but eventually nothing more can break, right?

 

[Eveready]

Triple check your battery terminals for corrosion and then check the other end of the battery cables. The end at the starter and the other one that goes to ground. Another strong possibility is the cable itself either the one to the starter or the ground. You are most likely to find the problem in one of those places. Since it still starts and runs my bet would be on the ground. Please report back to this thread when you find the issue and let us all know what it was. If those connections are OK the next guess would likely be the plug/connection at the alternator.

Edit: The more I think about this the more I think it might be a cable. Either way connection or cable replacing same would likely fix the problem. The reason I think it might be a cable rather than the connection is the flickering. Alternator connection is a strong second but if it were really bad you would be having charging and battery issues.

 

[mistaake]

Triple check your battery terminals for corrosion and then check the other end of the battery cables. The end at the started and the other one that goes to ground. Another strong possibility is the cable itself either the one to the starter or the ground. You are most likely to find the problem in one of those places. Since it still starts and runs my bet would be on the ground. Please report back to this thread when you find the issue and let us all know what it was. If those connections are OK the next guess would likely be the plug/connection at the alternator.

Edit: The more I think about this the more I think it might be a cable. Either way connection or cable replacing same would likely fix the problem. The reason I think it might be a cable rather than the connection is the flickering. Alternator connection is a strong second but if it were really bad you would be having charging and battery issues.

Hi, I decided to do the easiest and cheapest thing I could, which was add a ground cable between the negative post (yay for dual terminal batteries) and the nearest bolt... which was the one that holds the horn on. It made a HUGE difference. Barely any flickering and it cranks a lot stronger now. Also, I noticed when I put on the turn signal the voltage gauge doesn't move nearly as much as I did before. So, pretty much we can say with certainty I have a bad ground. Now, looking at the wiring, from the negative post there is a little tiny wire that goes right to the body and then a big one that goes down in a loom somewhere. I take it that the fat one is the problem? I mean, really I could leave it the way it is now but I'd like to actually fix the problem in case I need to ever install a non-dual-terminal battery for any reason.

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[Eveready]

Hi, I decided to do the easiest and cheapest thing I could, which was add a ground cable between the negative post (yay for dual terminal batteries) and the nearest bolt... which was the one that holds the horn on. It made a HUGE difference. Barely any flickering and it cranks a lot stronger now. Also, I noticed when I put on the turn signal the voltage gauge doesn't move nearly as much as I did before. So, pretty much we can say with certainty I have a bad ground. Now, looking at the wiring, from the negative post there is a little tiny wire that goes right to the body and then a big one that goes down in a loom somewhere. I take it that the fat one is the problem? I mean, really I could leave it the way it is now but I'd like to actually fix the problem in case I need to ever install a non-dual-terminal battery for any reason.

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It smelled like a ground. Glad that improved it. I expect the best way to do a real fix would be to replace both battery wires. At the time you do so wire brush the hell out of the connections at the starter and of course the battery ground. All those wires are the same age so don't be too surprised if similar issues arise anywhere there is real amperage on a connection or a ground that has a chance of corrosion.

 

[Elroy]

my cables have corrosion under the insulation which seems common, replace them