06 is heating up pasaanger battery and low voltage.

[Rogue Diesel]

Need some help guys. I have a 2006 cummins with 70k on it and the other day when I went outside to start it, the voltage meter was reading about 11/12 volts and my lift pump under my truck was screaming loud like it was running 10,000 Rpms and the volts wouldn't come up to normal operating range e.g.14v. So I looked under the hood and noticed the pasanger battery had acid bubbling out of the top of it. I immediately turned the truck off and tested the battery and it was no good. The driver side battery tested okay though. I just put new batteries in the truck back in 2015. So I went down and bought a new battery and put it in the truck and as soon as I started up the truck, the lift pump sounded like it was preparing for lift off again and my volts were still around 11/12v. So I shut the truck off and checked all the connections and made sure all the grounds were good to go. I started the truck back up and the volts jumped up to 14v like normal and my lift pump was functioning normal as well. So I went down to homedepot and picked up some stuff and when I went to start the truck again it went back to 11/12v and high rpm lift pump. So I headed back home and shut the truck off and let it sit for a second and started it up again and it went back to normal operations, i.e.14v. So once again, shut the truck off looked under the hood and didn't find anything. Started the truck one more time and it's back to low voltage and high rpm lift pump. I disconnect the lift pump while the truck was running the low rpms and that made no change. Also the new battery that I installed on the pasanger side was rather hot to the touch when I came back from homedepot, the old battery felt just fine. I did not test the alternator yet, account my multi meter crapped out on me today. (So maybe when I tested the battery's with that meter it could have given me bad info.) Anyway I could really use some help figuring this out.

FYI, I have an airdog lift pump.

Thanks.

[RDPsmoker]

You have a bad cable. ECM isn't seeing charging voltage so it keeps cranking the voltage up. I'd bet it's the cross over cable.

[homewrecker]

^^^ what he said. Charge is detected from driver side battery. Alternator output is to passenger side. Corrosion on ends or under insulation on crossover cable


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[Rogue Diesel]

I will take a look at that tomorrow. Thank you.

[Rogue Diesel]

So I just picked up a new multi meter and with the truck running the drivers side battery reads 12.2v and the pasanger side battery reads 18.9v. The alternator is reading 19.5v. So some how the system is over charging just the one battery and the other battery isn't getting enough of a charge. I have checked all the wires and everything looks to be in good condition. Not sure where to go from here.

[ComnRailPwr]

Change the crossover cable that runs across the top of the radiator and stop farting around. It can be bad and still look good. A good test is to just hook a jumper cable from positive to positive on both batteries and everything should go to normal. If it does you know 100% you have a bad cable.

[Mark Nixon]

Don't discount the ground cables being shot!
The other end of the circuit is just as likely to cause the issue, too!

Mark.

[crackerman]

It never hurts to disconnect all battery connections, wire brush, clean, reinstall with some deox and new hardware. That will make all the difference in the world.

Charging system works as so.
Pcm sees batt voltage at drivers side battery.
Alternator charges passenger side battery first, then through cable to drivers, where pcm see voltage.

Break that chain, pcm ramps up output, kills passenger battery.

[Rogue Diesel]

Originally Posted by ComnRailPwr

Change the crossover cable that runs across the top of the radiator and stop farting around. It can be bad and still look good. A good test is to just hook a jumper cable from positive to positive on both batteries and everything should go to normal. If it does you know 100% you have a bad cable.

I unplugged the field wire from the alternator and with the truck running it puts out about 12.3v. So that makes me the think the PCM is okay. I tested the alternator while the field wire was discounted and it read about 12.8v. Soon as I plug the wire back in, the volts jump back up to 18.5v on the pasanger battery and 19.6v on the alternator. I'm okay with changing the crossover cable but I don't think that is the problem.

What do you mean by hooking up a jumper cable between the two batteries? Please elaborate?

[ComnRailPwr]

Originally Posted by Rogue Diesel

What do you mean by hooking up a jumper cable between the two batteries? Please elaborate?

Exactly as it states. Take a jumper cable and connect the red clamp to the passenger battery positive, connect the other red clamp to the drivers side battery positive.

If problem goes away then change crossover cable.

If problem doesent go away do the same steps as above with ground terminals.
If problem goes away then it's a bad ground wire.

[CorneliusRox]

Originally Posted by Rogue Diesel

What do you mean by hooking up a jumper cable between the two batteries? Please elaborate?

Just basically pretending the jumper cable is the large positive cable that connects the two batteries. If that fixes your problem, then you know that you're just not transferring enough current over that line, and you know you need to replace it.

[Rogue Diesel]

Originally Posted by ComnRailPwr

Exactly as it states. Take a jumper cable and connect the red clamp to the passenger battery positive, connect the other red clamp to the drivers side battery positive.

If problem goes away then change crossover cable.

If problem doesent go away do the same steps as above with ground terminals.
If problem goes away then it's a bad ground wire.

I just tried the jumper cable idea. I left the pasanger battery positive terminal disconnected and left the drivers side positive connected so I could start the truck. Hooked the jumper cable up to both positives and both batteries read14.4v and the alternator read 15.2v. So I think I have a bad cable. I am pretty sure that is normal operating range for the batteries when the truck is running.

Thoughts?

Thanks in advance!

[wideopen]

Sounds like you found the problem.

While in there check your grounds, if nothing else but for giggles.

[RDPsmoker]

Crazy almost like most of us helping have seen This problem before

[CorneliusRox]

Originally Posted by RDPsmoker

Crazy almost like most of us helping have seen This problem before

Some just have to find it for themselves. My wife tells me that's called being a man

[Rogue Diesel]

I bought a new positive battery cable and problem solved. Thanks for all the help!! Next time I won't screw around. ��

[Rogue Diesel]

Originally Posted by RDPsmoker

You have a bad cable. ECM isn't seeing charging voltage so it keeps cranking the voltage up. I'd bet it's the cross over cable.

Thanks for the help.

[RDPsmoker]

Glad it was a simple fix!