vcoyle

I saw a similar thread about this but still need some help. Friday, I try to start my Dodge and it doesn't crank, can't jump start it and the only way I finally got to crank it was to roll it and pop the clutch. Took it to the dealer and by the time I got there the passenger side battery was spitting battery acid everywhere. Naturally they want to change the batteries. $400 dollars later they think it is the alternator and want to change it for $500. I take it to another place instead to change it for $350. Unfortunately this does not solve the problem and the new place thought it might be the belt tensioner. So another $100 later I'm still having the same problem. Putting a volt meter onto both batteries individually while running, both batteries are reading around 14.5v. After a few minutes the passenger side battery will start to slowly push the caps up and there goes the acid. I've cleaned all connectors to batteries and I don't know what else to look for. Thanks for all of your advice.

torquefan

If the charging voltage to both batteries is 14.5 and doesn't increase from there when RPM is increased, it sounds like it is just a bad battery, and you should just replace the pair of them.

vcoyle

even if they are both brand new batteries? should i go to autozone and have them tested? I'm getting the same results that i got from the old batteries is why i'm asking. I'm hesitant to go back to the old shop b/c he told me the problem was resolved.

vcoyle

Forgot to mention, when looking at the voltage on the dash, it fluctuates from around 6 to 14 to about 16 but I never saw the fluctuations on my voltmeter when touching either battery.

torquefan

I guess I misread the post and didn't see the battery replacement part. Sounds like we can rule those out. If the dash gauge is going higher at times, it makes me think that there are higher voltage spikes that your meter isn't seeing.

megawhite

there is a battery sensor located under the drivers side battery that, if i understand correctly, measures the temperature of the battery to assist the pcm in keeping them charged. i had this problem too, but new batteries solved my issue. i didnt have to check the sensor im refering too, but i did take it out and clean it best i could...

judgester

This sounds exactly like what happened to me, I have a thread on here about my battery exploding. I dont 100% understand what my issue was but I found a code with my smarty that showed something to do with the ECM losing power, which might have been telling the alternator to overcharge the passenger battery. I cleared the code and the truck is normal now. I would assume the dealer scanned the system for something like this already but you might want to double check.

vcoyle

I'm very disappointed in the dealer and the salesman i dealt w/.. the fact that the dealer told me it was the alternator and I went to another place to have them change the alternator just to end up w/ the same problem. I didn't ask this shop to test anything else. After they changed the alternator, I drove around to find that I am still having the same problem. New shop thinks it's the computer. So I'm now left to hunting for a new computer $400 or buying an OEM for $1800. I just wish the dealership would have seen that it was the computer by testing the alternator first.. .very odd. Can I do any testing w/ the smarty jr?

White Ghost

i had the same problem . i ended up replacing the cables on my truck . it could also be the voltage regulator in the ecm.

vcoyle

Since this is my only vehicle, I'm in a pickle trying to test everything and spend the least amount of money. Kicker is you can't return the ECM if that's not the problem.

vcoyle

well i went ahead and bit the bullet and ordered the ecm. keeping my fingers crossed..

White Ghost

good luck

vcoyle

well it appears to be the ECM. Replaced and it is running like a champ. $1400 later....

WilderMike

I think I read somewhere that the PCM actually regulates the voltage.. maybe a reflash could have saved some $$$$ ?? Bummer deal....

Old Smoky

FWIW - Both times I have seen the passenger side battery over charge ("explode") was caused by poor cable connections on the positive terminals. You can just stick your volt meter on the battery posts on the drivers side, and then on the passengers side, and compare voltages. You can also check voltage drop across various battery connections. Apparently it is possible for the truck to read low voltage at the drivers side, then charge the passengers side to try to bring the voltage up, all because of a poor connection on the positive cable connecting the batteries...