Charging Issues

[KEEP3R]

Hey all,

I got my new-to-me truck just about two weeks ago. 2005 2500 CTD with 88,000 miles. Last weekend I was driving and everything was fine, then suddenly the "check gauges" light turned on and my voltmeter read 0 volts. The Truck was driving fine so I finished my drive. Hours later I go to drive home, and it starts up and reads just over 14 volts. Great. EVerything is normal and it was probably just a weird glitch.

Fast forward 2 days and it did it again. This time the voltmeter remained 0 volts even after restarting the truck. I stop at O'Reilly's after work on my way home to get the batteries/alternator tested. I open up the hood and the passenger side battery has blown its caps off and there is battery acid everywhere. I quickly get some baking soda and try to clean it up the best that I can. O'Reilly's proceeds to test the batteries and they pass to my surprise. The alternator did not pass saying it was the voltage regulator... OK, that starts to make sense, maybe the alternator overcharged that passenger side battery. So I do a quick Google search and I find out the ECU/ECM contains the voltage regulator, not the alternator. OK, so I replace both batteries and the alternator just to be safe.

After replacing both the batteries and alternator, I drove it for 20-30 miles with no issues. Yesterday, the light came back on. I pulled over immediately and stuck my multimeter on the passenger battery and it said 12.5volts. OK, a little low but it's not over charging. The driver's side battery read the same. I'm going to clean up the grounds and throw new terminals on the battery cables, but that doesn't really give me much hope.

Does anyone have insight on this? Really starting to get discouraged after just purchasing this truck.

 

[p-Bar]

Put the volt meter on when truck is running it should read about 14.2 volts. Remember they batteries are paralleled so you will get the same voltage of of both. One bad battery can trash the whole system. I think you had a bad battery. Side note 2005's are notorious for cold solder joints on the instrument panel so be prepared for that.

 

[KEEP3R]

Put the volt meter on when truck is running it should read about 14.2 volts. Remember they batteries are paralleled so you will get the same voltage of of both. One bad battery can trash the whole system. I think you had a bad battery.

Thanks, after replacing both it still has the issue, sometimes its at 14.4v, sometimes its at 12.5v. This problem seems to be intermittent

 

[p-Bar]

Go through the the connections and check the grounds also. Need to figure out if it's the gauge,can you hook up 2 wires from the battery and run them into the cab so you can hook up your voltmeter to monitor and verify stock gauge is ok? You can tap power from the cig. lighter too.

 

[KEEP3R]

Go through the the connections and check the grounds also. Need to figure out if it's the gauge,can you hook up 2 wires from the battery and run them into the cab so you can hook up your voltmeter to monitor and verify stock gauge is ok? You can tap power from the cig. lighter too.

Thanks p-Bar, i will try that. Never thought that the gauge could be wrong.

 

[Ozymandias]

The gauge tells you what the ECM want to tell you, Zero Volt usually means the Alternator doesn't charge - but there is still some Voltage in the System.
Check the battery pole connections and heavy gauge Wire that connects both + batterys. Because the Alternator charges the passenger side battery, but the ECM reads the driver side battery.
Also there is a temp sensor below driver side battery, if that is broken the Alternator still charges but the Volt gauge goes to Zero to inform the Driver about the issue.

 

[p-Bar]

Good info Ozy

 

[KEEP3R]

Thanks for the assistance. The next step I did was replace the positive battery terminal because the crossover cable bolt was sort of loose and wouldn't tighten anymore without spinning. That has seemed to fix the issue... For about 50 miles I rode around with a multimeter taped to my windshield with it connected to my passenger-side battery. Haha, wasn't pretty but did the trick to help give me charge info on that troubled side.

I have about 175 miles on the truck since doing the terminal with no issues. Thanks for the insight everyone.