So I was on my way home the other day when I started to notice the smell of sulfur and the battery gauge reading less than half. I got home and popped the hood to see the battery boiled and acid all over. Had a mechanic buddy of mine check both batteries and the alternator and all were over charging. After some reading I've found out that the ECM controls the voltage regulation and could be screwed. Does anyone know how to test to determine which it could be and possible causes? Also, am I stuck buying one through Dodge or can I get one through Cummins? Thanks for any input.
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cummins crazy
Bad Alternator or Bad ECM?
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There is also a temp sensor on the battery. It's used by the ECM to limit overcharging. Be sure to check that sensor before spending money on whole new ECM
Also check connections very well. The wire in between the two batteries often causes this because the battery with the weak connection shows high internal resistance. That tells the alternator to put out when in fact, one battery is fully charged already. It will boil over the charged battery.
Test the wire with an ohm meter and wiggle the connections (lug to wire) while doing it.
Having only one good battery can trick the alternator in the same way.
In the marine world it's "code" to have a battery isolator to eliminate this potential hydrogen bomb in a closed environment.
Test the wire with an ohm meter and wiggle the connections (lug to wire) while doing it.
Having only one good battery can trick the alternator in the same way.
In the marine world it's "code" to have a battery isolator to eliminate this potential hydrogen bomb in a closed environment.
^^^^ Agreed.
Double check the wire that connects the two batteries and CLEAN all of the termals real good. Boiling batteries happens alot and this fixes the problem 99% of the time.
Double check the wire that connects the two batteries and CLEAN all of the termals real good. Boiling batteries happens alot and this fixes the problem 99% of the time.
The positive cable from the passenger side to the driver's side is usually the culprit. Clean and tighten all battery connections.
the alternator is directly connected to the pass. side batt.
the ECM reads and sets charge condition directly connected to the driver side batt.
if the paralleling crossover batt. cables corrode or loose connection,
BIG PROBLEM.
fried overcharged pass batt. and
discharged dead driver side batt with
no crank.
the ECM reads and sets charge condition directly connected to the driver side batt.
if the paralleling crossover batt. cables corrode or loose connection,
BIG PROBLEM.
fried overcharged pass batt. and
discharged dead driver side batt with
no crank.
The cables are clean and tight. What do you need to look for when checking the temp sensors? Amount of voltage, resistance?
my 06 did the exact same thing. Peel the plastic back on the cables, they are coroded up inside. I had to cut the factory ends off and some of the cable to get a clean cable. Never had an issue after that. I would check that before doing anything else but its your money and time so it dont matter to me
It was a bad driver side battery connection. The clamp had melted a little bit from arcing out and the first time I checked it was snug. Once the truck was running for a while, my buddy went to check with the multimeter again and noticed the positive clamp was heating up. I changed out both batteries, they were getting old anyways so it was good timing, and it's been fine since. Thanks again guys.
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