How does the first gen regulate from altenator to battery?
 

Old cars had voltage regulators, IIRC, the dodge diesel had a "program module" - not a stand alone voltage regulator. Back in the early 2000s, maybe off this board, I bypassed the computer on my 98 and actually installed an old fashioned mopar voltage regulator, but it's been so long I have forgotten where I got it from and how. Anyone done this to a first gen?

IMHO the regulators you get now are mostly junk so I wouldn't go there. I used the transpo 8315 kit on my 90 plowtruck (it will also work on the newer computer controlled thrucks) and doing fine after 3 years, you can also get a one wire alternator that's internally regulated although they are kinda spendy

Oh, this is exactly what I needed to know- will this work on our CTD?

https://www.ebay.com/itm/38440864579...hoCtFsQAvD_BwE

Not sure I always just used the transpo kit

To answer the original question on a 90 anyway. The vr uses a contact on the ignition switch to determine the battery voltage. The problem that happens is that rust and other crud on that wire causes resistance which lowers the voltage reading and causes overcharging of the battery. Anything 15 volts or more will destroy the battery quickly, ask me how I know. The easy solution is to run a wire directly from the battery to the vr through a relay. There are only two ways that overcharging happens, a bad vr and resistance in the control wire. There are a few good threads on this…Mark

I just bought this one, hope it works!

On my truck after I installed the kit I had to unplug the regulator to make it work

I cooked my battery also because of this. The relay fixed it and it has been rock solid at 14.2 volts ever since. I finally bought a genuine Mopar VR because the O'Reilly ones kept crapping out. That gadget off ebay looks interesting but I have no experience with it. If you go with Mopar VR and relay make sure the case of the VR has a good ground also. I ran a separate wire for the ground to make sure.

Edwin

Hi Edwin I hope you are doing well in Ok. Rust is the primary problem in most of the weird things these trucks do in regards to electrical problems and ground checking should be first on the todo list. Mine burned up a 350 dll odyssey a few miles from home and there was really nothing I could do about it alongside I-10. Rust complicates diagnosis of weird electrical problems. I live in sunny Az and still get fooled by hidden rust. I can’t even imagine how it is in the rust belt… Mark

My truck spent it's early life in southern TX so very little rust. Since I plan to stay home on icy days here and drive the wife's AWD Chevy I hope to avoid most of the salt problems.

We looked at AZ as a place to move to on our escape from Commiefornia but property prices were just to high. The price we paid for this place was just to good to pass up. $35K for a house, garage outbuildings and 2 acres.

Hope you're doing well.

Edwin