ridepayson

My truck isnt charging, I found a similar post to the problem I am having in the 12v engine and drivetrain section titled "1995 charging problem" --- I just posted the following there:

Hi all -- Fantastic information!! I am hopeful this fix discussed here will work on a '97 as well? I havent been driving my truck for months due to this same charging problem, and not wanting to spend the $500 on a new pcm that works fine --- except the regulator. Only difference in the problem I have read is ataboy9026 had a check engine light come on, and I have a gen light on, no check engine light ever. My truck is a 3500 4x4, manual, if that matters in this situation. Any of your insight and expertise would be appreciated greatly!! Thanks in advance --------
Anyway, I thought I would post here as well -- I need to get my truck back on the road by the weekend, and need some help. If any of you have had similar problems or know if the parts are interchangeable, Please let me know.

JKM

Does your tach work? a/c work?

Fill in your signature so it will make it easier for everyone to help you.

whazzup

I had a similar problem, no check engine light but the generator light coming on and volts going way down. Took it to a auto repair facility and the wanted to butcher my wiring and install a external regulator. I said no.

I did some trouble shooting and found that the grid heater relay was toast (just unhook the wires) 72 dollats and all was fixed.

FWIW

dzpoorjr

Hey nice to see some more Arizona Cummins guys!

ridepayson

Tach and a/c are both working, checked grid heater, it's fine, alternator puts out 15.5 on the bench, so I am guessing its the regulator.......Is there a site that has an actual diagram that is year specific for installing the external regulator? I bought a regulator for a 79 dodge 318 as per another post on this site, but I am still unclear on installation --- I just dont want to do any further damage................thanks to all for the help!!!

infidel

Picture is worth a thousand...
wires from alt are interchangeable

Friend who likes to be prepared installed one with a switch to cutoff the positive feed so if his pcm regulator ever goes out it will only involve flipping a switch to prevent getting stuck somewhere.

ridepayson

PERFECT!!!!!!!!!!! A million thanks infidel!!!

mt72916

i just did this on mine I used a new 79 dodge reg $8.00 and a
repair pigtail harness for the 79 voltage reg $5.88 it was a Standard P/N S-573

that makes making regulator connections easier and I didn't have to try and find a used one.

I mounted mine right above the altenator on the altenator bracket. I slightly bent the regulator mounting ears to conform to bracket. the regulator connector is facing the alt connections and firewall. i drilled and tapped the 3 holes for 10-32 screws and got a sufficent ground that way and did not run a separate wire for grounding the altenator i placed star washers between reg and mount.


the original wires on my nipponso alt connector were in this order:

longest heavy lead went to the alt output.

the short heavy lead is grounded to alt.

the small lead closest to the heavy leads is power from ASD relay (battery positive when enginge runs) hook there to get power for input to regulator Blue wire on pigtail.

the lead closet to the fan is normally the regulation wire from the PCM and provides a varible ground in normal operation. green wire leave this lead open on old harness.

i used a 4 foot starter replacement 4 awg wire and new ends to hook up to the 2 heavy wires and and routed the new wires back to the alt.

I hooked the regulator wires directly to the alt then pulled power from the small lead ASD circuit and hooked it up with the blue wire on regulator to provide power to regulator.
had to splice them to reach studs.

I taped all connections and wire tied the old harness out of the way
that way i did not disturb the original wiring harness in case it is need later .

sorry about the length of this I hope this helps

mel

ridepayson

Thanks to all who have helped -- going out right now to see if I can make this work............. will post the results!!!

ridepayson

works like it should!!!! Again, thanx a million for all your help! Got the charging problem fixed, now off to tackle the four wheel drive issue.....................Just problems faced living down the only road in the state that is bladed with a post hole digger!!!!

ridepayson

spoke too soon....... charged fine for about 20 minuites, then right back to square one?????????? Even with the external regulator..... Any more ideas? I give up.

MnTom

Try reading this : https://www.dieseltruckresource.com/...tage+regulator
There might be something here that can help you. There are instructions for testing the alternator there too.
Tom

boiler-rat

I went through all this head ache a while back. After I installed the ext. reg. it quit charging after a few days. It was the brushes in the alt. They were at the point where it would charge intermittently. If yours is a Denso alt. they are real easy to change. Dont know about the other brands of alt. Run 12v to the 2 small terminals on back of the alt and then check alt. output. That bypasses the reg.