Diesel-Dan

Getting some weird stuff happening here on a cust truck. He has a 1997 Dodge 2500 CTD. His is getting a charge and then it will quit. Very intermitant. The alt was checked to be good. Someone told him that the voltage regulator was in the computer...which sounded a little fishy to me...but i have see weirder things. He said when it charges, it seems to over charge baised on the dummy gauge. Dealer and other have said he needs a new computer....that seems a little bit rash and strange for a charging prob to me. Any suggestion?

Dan

gunracer1

any chance it is his grid heater kicking in?

Diesel-Dan

Good point...but its running down to where the truck just dies....i think the heater sticking would cause wires to heat up to the point of meating insulation. At least to the point of draining the batt while driving.....

gunracer1

i don't think they will evey melt the insulation. just disconnect them, 10mm nut, and give it a try

Diesel-Dan

will do....thanks for the info

kd460

Yes, the voltage reg. is in the computer. You can bypass this and run a more conventional setup per "haulin-in-dixie" instructions. Do a search under that user name. Maybe he'll chime in. What about checking the brushes on the alternator.

Let me know if you can't find the post, I"ll try and dig it up. Kevin

Diesel-Dan

10-4...ill start digging

Diesel-Dan

https://www.dieseltruckresource.com/...tage+Regulator

CAPTNDAVIE

Mine did a very similar thing and it was the brushes. On the alt if you ground one of the small studs and put 12 volts on the other the alt should put out max. I am talking about the two small studs that part of the wiring bolts to. The computer sends more ground to the alt as it needs to charge more. The alt guy showed me this. Also it doesn't matter which one you ground and which one you make hot. And you will need to disconnect the main cable and use a test meter to see how muchnit is putting out.

got...DIESEL?

I wouldn't ever open circuit an alternator by removing it's main output wire or breaking its ground. The rectifier will (or can be) damaged. Full fielding the alternator does produce higher than normal voltage but usually not enough at idle to hurt the ecm/pcm. You can always turn on a load or two to bring it down some too.

Chris

richard.koon

I am having the same issue, but along with not charging my transmission is staying in first gear, but if i drive it until its dead wait until the next day and jump start it everything is back to normal.. then when I turn it off and turn it back on back to no charging and not shifting.

Changed:
CPS or ESS
Alternator
ASD relay

James Pyron

I just did the external volt reg swap on my 92... before the volt gauge would drop to 8-10v I could tap on the pcm and it would go back up again.... anyhow I got a volt reg for a 87 dodge 5.9l gas from the parts store it was $17.... I removed the connector on the alt ( black box ) but I left the factory big cable from the battery and the ground to the engine block....I ran 2 wires one from a key on power source to one pin on the volt reg and spliced into that one and ran it to one of the exciter pole on the alt the other wire I ran from the other pin on the volt reg to the other exciter pole of the alt..... I started the truck and the volt gauge wasn't reading but 6v, so checked the volts on the exciter poles I was getting 12v in and out so it was charging.... it took me awhile to figure it out but is all it was since I ran new wires nothing was going to the volt gauge.... I traced wires and found the green/org ( from ignition to the plug on pass fender)wire is the 12v power to the exciter pole factory ( it changes to I believe a blue wire at the plug rite before the alt ).... the soild green wire is on the other exciter pole and goes to the volt gauge.... I just cut the green/org wire close to the pcm and covered it with heat shrink and spliced Into the green wire and now the gauges reads correct and no check engine light.... I also mounted the reg on driver side fender and it's grounded by the self tapping bolt to the fender and the body is grounded to the engine so no need to run a ground from alt to reg.... that's my experience with it and it's working great it's been 2 months since installed

Robert Rausch

My '95 was alternately charging and not charging, along with the Check Engine light coming on and some other weird electrical symptoms. I had an O'Reilly's "Lifetime" alternator on... it had lasted 4 years. I took the alt. back in and got another rebuilt one from O'Reillys, BUT... the alternator I put back into my truck was the original that had lasted 350,xxx miles and that I saved and had rebuilt by my local rebuilder. I've got the O'Reilly's now as a spare. Anyway, long story cut short, a good alternator fixed the problems.

Gary Lambert

I have a 91.5 12 valve that is intercooled and it started blowing the caps off the battery and now it's only putting 1.11 volts to the battery the regulator has 12 volts running through it and has been grounded to the battery directly??? I have 2 different alternators that both tested good and neither are putting out the right voltage on the truck! Please help!!!!

texasprd

Gary, did you mean to say "1.11 volts" or "11.1 volts" ?

Is that a single battery truck? I'm not familiar with the system on a pre-94 truck, so I don't know if you have single- or dual-battery...

What voltage are you getting off the back of the alternator? (It really should be a bit higher than 12 volts)

If you disconnect the battery completely, what voltage does it put out?

The statement of 1.11 volts is amazing me - if that's true, I think something catastrophic happened in your battery (shorted, perhaps?). How often does it blow the caps off? Under what circumstances?

I think the troubleshooting path is influenced by the actual battery voltage. 11.1 volts could be due to extremely corroded cables/connections - 1.11 might be a wrecked battery (shorted/exploded)...

We need to know more...