Do battery cables go bad?

[4570Man]

You take a reading at each end of the cable. Forget the voltage, you are only interested in the difference. It would be handy to have two meters calibrated the same and connected with clip leads. But again, taking good readings of this miserable 12 volt system in a dirty environment can be challenging.

I don't even like to bring my FLUKE stuff near some dirty old engine! lol

I agree 12 volts is stupid. I think there would be a lot less problems if it was 50 volts or higher. You hardly ever see problem caused by a loose connection in a 110 volt system.

 

[zombie]

How do you load test a cable without the battery drop ruining the test?

The battery doesn't have an effect on the test. I think there is some confusion on just how to perform a volt drop test. To perform a volt drop on a positive cable that goes from the positive post of the battery to the starter, you would set the multi meter to dc volts within the system voltage range if your meter has that option. Some are dc volts and you can set your decimal point with a range button, others have different voltage selections. Set your range for xx.xx volts. The meters with voltage selection usually have 20 volts as the lowest setting, use that one. Now pick one of your meter leads, doesn't matter which one, and hold it on the positive post of the battery, take the other lead and hold it on the other end of the cable at the starter. Crank over the engine preferably with ignition disabled to get a good consistent reading. What ever voltage the meter shows is how much voltage the cable has dropped. On a positive cable, .5 volts is the max you want to see. On a ground .3 volts is the max you want to see. You can even test connections the same way. One lead on the positive post itself, and the other lead on the terminal that is clamped to the positive post and crank over. This will let you know if there is corrosion within the clamp. With a meter set on voltage, it measures difference in potential between the two leads.

 

[RickB]

Q

I agree 12 volts is stupid. I think there would be a lot less problems if it was 50 volts or higher. You hardly ever see problem caused by a loose connection in a 110 volt system.

Until the building burns.

 

[Industrial Toys]

No! It's a VALID point. 24 volts would have been so much better. Just look at the crappy performance of 3 volt flash lights over the years, shaking them to get going, just to get some contact. Higher voltages ARC and virtually weld their connections.

A starter motor armature would see so much less current and heat as well.

 

[4570Man]

Q

Until the building burns.

What happens when a massive amperage 12 volt cable frays and shorts out against the the frame?

 

[4570Man]

No! It's a VALID point. 24 volts would have been so much better. Just look at the crappy performance of 3 volt flash lights over the years, shaking them to get going, just to get some contact. Higher voltages ARC and virtually weld their connections.

A starter motor armature would see so much less current and heat as well.

And you could use a lot smaller battery cables and boosting would be easier when the time comes.

 

[tjkubota93]

Your dump truck is a chevy right?

Alot of them "back in the day" wouldn't start well when hot.

A heat shield on the solenoid will fix that problem.

 

[tjkubota93]

Theres about a million different ways to do it. Fixed more than one car that way.

Some guys put a ford solenoid up on the fender. I haven't done that.

The poor little solenoid doesn't like living next to the exhaust manifold. On a hot soak (sitting after running a while) things "soak up" the heat and are hot all the way through.

 

[tjkubota93]

Just read first post. Dont know if diesels had the problem. I was thinking sbc/bbc. Its still a possibility.

Get new cables that are made for the truck. No universal crap.

 

[D2Cat]

I thought Ohm's law described why armadillos were coming up from N. Texas into Kansas.