Dodge diesel battery discharge

Batel · Feb 4, 2016

I've got a good friend with a 2005 Dodge 3/4 ton 4 x 4 5.9 Cummins he uses daily, pulling, hauling daily driver etc. He tells me every so often his batteries end up dead overnight. He's checked the common stuff, interior lights etc. A couple of local mechanics have convinced him the computer integrated voltage regulator is the problem and he's now intent on wiring around it, up to and including trying to put a 1 wire Delco on it. I'm not convinced it's the regulator since it's intermittent. I've not found a lot on the Dodge forums addressing the issue. I told him to call me sometime when it does it and we'd put a charger on it and I'd go through the fuse boxes and see if I can see the draw but our schedules haven't matched up yet.

Has anyone run into this before? Any input would be greatly appreciated.

bobs old iron · Feb 5, 2016

couple of things come to mind, [1] how old are the batteries, on my 2004 dodge, it is the pass side battery that is bad and drains the system down, and of course, in winter, brings out the worst in them, i replaces them both,, [2] does he have any extra bolt on, radio, eletric goodie, that can drain juice even if key is off...

Batel · Feb 5, 2016

(quoted from post at 23:57:49 02/04/16) couple of things come to mind, [1] how old are the batteries, on my 2004 dodge, it is the pass side battery that is bad and drains the system down, and of course, in winter, brings out the worst in them, i replaces them both,, [2] does he have any extra bolt on, radio, eletric goodie, that can drain juice even if key is off...

Both of his batteries are new (and check good), he doesn't have an after-market sound system. He does have a trailer brake controller which I'm suspicious of but I don't know how it's wired, so I don't know if it's hot all the time or not. His problem is so intermittent that I haven't been around when it happens, maybe every week or two.

MSD · Feb 5, 2016

The brake controller stays hot all the time or at least the trailer battery lead.

MikeinKy · Feb 5, 2016

I have a 2003, and my batteries go down if I leave the key in the ignition. If I take out the key, it is OK.

Batel · Feb 5, 2016

(quoted from post at 19:13:52 02/05/16) I have a 2003, and my batteries go down if I leave the key in the ignition. If I take out the key, it is OK.

That's interesting that just leaving the key in would run them down. I'll have to ask him but I'm pretty sure he's like me and doesn't leave a key in anything of any value.

Batel · Feb 5, 2016

(quoted from post at 14:11:27 02/05/16) The brake controller stays hot all the time or at least the trailer battery lead.

The brake controller is my suspicion but it's hard to catch it doing it.

ASEguy · Feb 6, 2016

When I worked at a Dodge dealer we found at least 90% of the truck electrical problems could be traced to aftermarket add-on's. I would be unplugging them on a daily basis, one at a time, to see if one is the culprit. That said it takes a pretty good drain to take them both down. Check the charging voltage at both batteries prior to start. A fully charged battery should read 12.6 - 12.7.

T in NE · Feb 8, 2016

If he wants to bypass the computer on voltage regulation, the thing to do is swap in a self regulated 200 amp unit from a heavy duty truck. Takes a little work fabricating the mount but it can be done.
Or you can convert the dodge alternator to self regulation.
I don't know how the computer would like losing control of charging, though. Might throw fits over it.

souNdguy · Feb 9, 2016

check the light in the glove box. er actually.. the switch for the glove box light.

i had a 98 dodge ram that if you left it a few days you could tell the battery would flatten though it would usually start. I chased that for weeks, and then it became a 2nd truck, so I put one of them battery disconnect switches on it and when i parked it, I'd kick the switch and it would be fine.

After a year of light farm use that way, i sold it to work, and then the problem arose again. ( I had forgot about it .. it was 2nd nature to turn truck off and throw the disconnect and walk away ).

Anyway. started troubleshooting it again. did the meter and fuse pull deal.

finally noticed the glove box lamp swtich plunger and the tab that pushes the plunger missing.

pulled the lamp.. no more drain.

fixerupper · Feb 10, 2016

Here is something weird that drew the batteries down in my 08 Dodge Cummins. The horn relay was activated full time. Something shorted in the horn switch causing the horns to blow on their own while it was sitting in the shed. I replaced the air bag/switch in the steering wheel with a used one and it worked for awhile, then the same problem sprang up. I unplugged the horns not thinking about the relay still being kicked in. It took two weeks for it to suck the batteries so I didn't pursue the matter for at least a year. This winter I started pulling fuses till I found it.

Batel · Feb 10, 2016

(quoted from post at 21:13:15 02/10/16)
Here is something weird that drew the batteries down in my 08 Dodge Cummins. The horn relay was activated full time. Something shorted in the horn switch causing the horns to blow on their own while it was sitting in the shed. I replaced the air bag/switch in the steering wheel with a used one and it worked for awhile, then the same problem sprang up. I unplugged the horns not thinking about the relay still being kicked in. It took two weeks for it to suck the batteries so I didn't pursue the matter for at least a year. This winter I started pulling fuses till I found it.

I really appreciate all the great responses and will work on it when our schedules meet up. He's 83 but hard to keep up with, he just drove 14 hours one day last week to pick up some 59 El Camino parts and a new bed for his truck.

I'm really apprehensive about putting an old model regulator on the truck because I don't think voltage, especially overvoltage is as well controlled on the earlier alternators. Especially since no one on here has had the integrated regulator drain their batteries. So I'm hoping to find just what the draw is before he resorts to that.

I saw him briefly last evening at a meeting and told him if his trailer brake controller is fused separately to pull the fuse for a couple of weeks to check that. (Just don't forget to hook up to a trailer and leave it out!)

If I find it I'll post a follow up so there'll be a resolution to this particular problem.

souNdguy · Feb 11, 2016

just as an update.

I pulled the plug and wires off my alt on my 98 dodge, and it still ran down so that will be one way to test and rule out the alt.

2SteveWI · Feb 15, 2016

I have 95 Dodge Cummins 4x4. With the old Brake controller the Manual Slide would not return completely. Just a fraction of an inch from the end, and the Batteries would be Dead the next Day. This Only happened a couple times until I noticed it. Replaced Controller, and never happened again. Steve

Dodgeit · Apr 24, 2016

(quoted from post at 00:24:41 02/05/16) I've got a good friend with a 2005 Dodge 3/4 ton 4 x 4 5.9 Cummins he uses daily, pulling, hauling daily driver etc. He tells me every so often his batteries end up dead overnight. He's checked the common stuff, interior lights etc. A couple of local mechanics have convinced him the computer integrated voltage regulator is the problem and he's now intent on wiring around it, up to and including trying to put a 1 wire Delco on it. I'm not convinced it's the regulator since it's intermittent. I've not found a lot on the Dodge forums addressing the issue. I told him to call me sometime when it does it and we'd put a charger on it and I'd go through the fuse boxes and see if I can see the draw but our schedules haven't matched up yet.

Has anyone run into this before? Any input would be greatly appreciated.

It's the radio dads 05 did the same thing chased it for ever good electrical guy found it and told pop a lot of 05s had that problem.

Dodge diesel battery discharge

Batel

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bobs old iron

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Batel

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MSD

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MikeinKy

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Batel

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Batel

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ASEguy

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T in NE

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souNdguy

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fixerupper

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Batel

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2SteveWI

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