hey, there, have a 2007 3500 mega cab, (5.9)

back in june, I killed the batteries listening to the stereo camping. jumped started, and all was well... besides the engine light ( code 2509) it went away.

today i was driving for about 1 hour. stopped at a rest stop. took a pee, and then started truck back up and before driving away noticed a little steam/smoke from under the hood passenger side.

it was my battery. leaking from the service caps. i quickly turned the truck off and disconnected that battery, restarted the truck with just the drivers side, and hurried back home.

went to dodge, but being a saturday they had only one tech, and didnt have time to look.

I should tell you that i have the edge cts monitor ( not a tuner) and it was reading 14.5-14.7 volts at idle and driving!

I went to a diesel shop, and asked for there opinion... they hooked my truck up to there charging/load tester, and were getting the same voltage as me.

(they hooked pos to pos neg to neg on the driver side battery, and then he had a clamp type device and clipped it to a part of the alternator ( maybe a wire)
he said it was reading 16 amps, but it should be more like 30! but said it could be because the other battery wasn't connected.

He recomended that since i had to replace one battery i better replace them both.

so on my merry way i went to my parts store. replaced batteries, and so far so good. all be it 6 hours later

Why did this happen?

I have done some searching on here, and read that it could be the alternator/voltage regulator. but if it was getting to much voltage wouldn't my edge monitor show higher then 14.5-14.7?

sorry bout the length

 

There is a battery temperatur sensor under the drivers battery that monitors the batt temp when it is charging. If that battery is weak, the computer keeps sending too much amperage through the charging system to charge the weak battery thus boiling over the stronger battery on the passenger side. That is why both batteries need to be replaced at the same time and be identicle. Bad grounds, corroded/loose wire terminals and cables could also be a cause.

 

Were you still on the original batteries?

 

im gonna say yes, they were the original batteries.... well 80% sure

 

Replace the alternator. I just had that happen on my 07, boiled the passenger battery (boy did that smell like crap). I also replaced the batteries, both of them, and no issues since.

 

My 04.5 5.9 diesel was charging 14.2 driver battery and 18.7 on passenger side , was told by dealer the voltage regulator was out and was in the PCM. Local shop strickly diesel said that 95% of the time it was bad cables, replaced cables ($460.00) problem solved.