I did the wiring on my 89 dodge 250 but now instead of overcharging the battery it's discharging it

 

Moving this to first gen Ram forum for you.

 

It originated in the 2nd gen section for a reason. It is for the 2nd gen Rams with a PCM failure. This needs to be moved back. lol

 

dirtydog or lxman1 will have to move it back to 2nd gen.

 

I got this link because I'm overcharging on my 92 Dakota and I know I'm in the wrong forum but you guys have been a big help and I even got a belly laugh when the guy said he fried his new regulator with the advise of hooking up to the 12v existing field terminal, lol. I'm worried about 15.9 volts compared to his 32v??? A 120 amp fuse??? Is this for real? Sounds to me like he's trying to run a 50 ton ac unit on a building or something sheez, the biggest fuse I have is a 30 amp circuit breaker on a high output fuel pump and a radiator fan!

Anyway it appears that I've got a short in my wiring since I've already tried a known good PCM and a known good alternator. Your forum has supplied me ammo to deal as I delve into this situation tomorrow and I thank you much...Dennis, aka Capricorn

 

Hey all running out of hair to pull.Two weeks ago battery stopped charging and so figured the alt.,took it off had it checked they said it was good and sold me a regulater got home and couldn't find where the ****in thing went.A friend said it was in my PCM but to just bypass it.How easy right... screwed the new ext. reg to firewall ,run ground wire from reg base to alt . bolt for good ground..green wire from alt. I cut at PCM ran to fire wall mounted REG.then Blue wire that is ign feed to alt I attached a short blue wire form there to the fire wall REG.....Hooked up battery cables ..15 volts ..ok maybe low .drove 50 or so miles smell something pull over. battery smoking. got new battery this week put in cranked great but charging at 17.5 volts.. could that new Reg have been bad??? hooked same as it shows at start of this post
..help..

 

I did this on my 97 12 valve and it did not fix the issue, new alternator, batteries test 12 volts, truck will run when jump started, voltage stays around 10-12, as soon as you shut it off, the batteries are dead..any ideas?

 

Fuse!

On my 98 there was a big fuse ffor the alternator. When cool it would make contact and as it warm up the fuse would separate and stop charging. (it's not the normal style it's a big square looking one)

 

Looking for some help here with my 91 Dakota 318 (I know wrong forum but this thread has exactly the people I need to fix it...I hope )

Battery died and was not being charged so I replaced the following so far:
Battery (was old and corroded anyways)
Battery ends
Alternator (tested at auto store for good measure)

After replacing all of this I still read 12V at the battery, alt batt post and both winding posts. According to what I've read here this should be correct, but the battery is still not charging. So I hooked up the external voltage regulator and I get the same thing. If I manually ground one of the field posts, the voltage increases until i remove the ground which leads me to believe either I have bad external regulator or something else is going wrong.

What exactly tells the external regulator to ground the one circuit?

 

I'm sorry I have been MIA for so long. I have had a very hectic year so far and it doesn't seem like it will let up any time soon. For those of you that have posted that this fix did not work for you, I apologize and I hope that the issue has been resolved.

As for the mod- If you do exactly what I did in the original post it will fix the problem of the regulator in the computer being bad 90% of the time. If there are any other issues it may not have the same effect. It worked perfectly on the 93 Jeep that I did it on and on a 94 Ram 1500. Both of these had the 5.2L V8, but I doubt if the engine makes a difference.

My only advice would be to make sure your wires are hooked up exactly like I had mine. If there is still a charging issue, then there is likely something else wrong other than the reg in the comp. This wiring setup is basically the exact setup that was used in the 1st gen and earlier dodges with external regulators. With the exception of not going through the fuse block and main harness.

Also the size of the fuse is dictated by the alternator amperage which can be anywhere from 115 amps to 175 amps, so the oversize fuse is a necessity.

I hope this will help some, and again I am sorry for not being on to help.