Big Voltage Drop

[Mattj96]

If you wire them in series that will make 24 volts. PLEASE DON'T DO THAT! It should charge the same at idle as it does when revved up. Makes me suspect the alternator is on the way out. You should only need one battery. If you want two it won't hurt but for the sake of troubleshooting I would run one (a good one) to narrow down the problem easier. See what size of wire connects your battery to alternator/ distribution block. Small wire makes for voltage drop.

I won't thanks, I always get series and parallel mixed up. Positive wires are pretty beefy, the body ground from - on main bat is thin and the screw holding it is pulling out so I'll take care of that. I'll check connections going to the power distribution system. Thanks so much!

 

[RichLo]

Parallel is fine (neg to neg, pos to pos) that is how they should be wired currently. But I agree that you dont need 2 batteries and running 1 at least until you figure out the root problem is probably your best bet at finding the problem. then once everything is good with 1 then you can go back to two if you want.

And yea, new battery cables are cheap and usually need replacement anyway if they are original but I also suspect your alternator is dieing slowly and may leave you stranded. If you only run 1 battery, you can keep the other once charged in the back of your truck if you need to swap them to get home.

 

[Mattj96]

Parallel is fine (neg to neg, pos to pos) that is how they should be wired currently. But I agree that you dont need 2 batteries and running 1 at least until you figure out the root problem is probably your best bet at finding the problem. then once everything is good with 1 then you can go back to two if you want.

And yea, new battery cables are cheap and usually need replacement anyway if they are original but I also suspect your alternator is dieing slowly and may leave you stranded. If you only run 1 battery, you can keep the other once charged in the back of your truck if you need to swap them to get home.

This is a very good idea I think I'll do that .Thanks a lot .

 

[Bob L]

I had an intermittant charging problem with my 98 and it turned out to be the plug on the alternator being bad.

 

[Mattj96]

I had an intermittant charging problem with my 98 and it turned out to be the plug on the alternator being bad.

By plug you mean one of the plastic harness things or one of the battery terminals? Just had the alt checked at AutoZone and they said it's charging as it should be .

 

[Eveready]

While you are at it check the quality of grounds.They are famous for getting corroded and not making good contact. I would start at the battery and make sure those ground connections are shiny! This definitely sounds like a bad connection somewhere.

 

[Mattj96]

While you are at it check the quality of grounds.They are famous for getting corroded and not making good contact. I would start at the battery and make sure those ground connections are shiny! This definitely sounds like a bad connection somewhere.

The ground straight off the main battery was attached to the body, and the screw holding it down was loose as hell, so i sanded down a spot nearby and threaded a new screw in and no problems so far. So you're probably correct. If it starts happen again I'll definitely be replacing all cables to and from battery. Thanks again, you guys helped me a great deal in narrowing this issue down and avoiding just throwing money at it. I love that these motors are so easy to work on, can see every cable path just standing over the motor.