I drive a 92 dodge cummins diesel 250 4x4. I'm having a problem with my battery losing power when I'm not driving it. This is a new battery, only 2 months old. When the truck is running, the battery registers at 13.5 volts. When I accelerate a bit it goes to 14.1 or higher the more i accelerate. When I shut off the truck, the voltage drops to 12.6 volts. Normal right? But the longer I leave the truck, the lower the voltage in the battery drops. Within the last 24 hrs, I'm down to 11.8 volts. Can you help me out here?

Thanks,

Jeff

 

completely disconect 1 bat, put an amp meter between the neg cable and the bat of the one still conected. 0.1a is normal any more than that and theres a draw. try pulling fueses untill it go's away. if its 0.1 or less , then you have a bad batery thats self discharging.

the tops of the baterys are clean, free of corosian and dry corect? if not it could be having a voltage leak between the terminals or to ground.

 

Also, check your cig lighters for change. I found a penny in my son in law's truck. The battery would draw down in two days due to the penny. Check dome lights, truck, hood lights.

11.6 volts is not good. 14.1 charging is good. You may have a bad batteries.

 

Could you explain your test better? Doesn't make sence to me.

 

While you are testing with a meter, pull the battery cable from the starter and check the solenoid for continuity. When the contacts start to corrode from old age and use, they make like a big carbon sink and bridge voltage to ground. If they are bad, go to foster truck for a new set of contacts.

 

You will need an ammeter to do this test. Remove the negative cable from the battery. connect the negative lead from the ammeter to the negative post on the battery. Connect the positve lead from the ammeter to the negative battery cable. Observe the reading. If the reading is more than 0.1 amps then you have a problem somewhere in the vehicle wiring. Go to the fuse panel and remove the fuses one by one until the reading on the ammeter drops to 0.1A or lower. This will tell you what circuit has the problem. From there you will have to follow the circuit out until you find the trouble.

 

Check the glove box and make sure the light goes out, the door warps and allows the light to remain on.

And check and make sure the key ring light goes out after about 15 seconds.
The thermal timer could be bad.

Check your hood light and be sure it goes out; if you park on a steep drive it will remain on.

Also check and be sure your brake lights are not on.
A bad brake light switch or a poorly adjusted brake controller could be the problem.
Jim

 

how do ya check glove light is out? I mean come on, I can just barely fit my 11 year old in my refridgerator when I close the door to make sure that light goes out..... Aint no way hes fitting inside the glove to check, he just ran out the door 'cause of the look I gave him, he knows somethings up.....