It used to be that you could just play with the regulator , then the altinator, and later you had the alt. & reg. on one container , now [ or should say in about 93 ] you've got them sepperated again , but now you regulator cost how much !!!
Oh it wasn't the $ 500 PCM , we'll have to check it again , relay , batt.ect.

How far did you go before you found the problum ? and how will you check it next time.

I've been in , now out of the auto repair buis for more that 25-30 yrs. and it seems that its back to one of my own deffintions of preventive maintance , make to prevent you owner from fixing it .

Long way around saying that my check eng. lite came on , then I noticed that the voltage gauge was low , 12v , pulled over and checked the codes , 12-battery disconnected within the last 50 cycles [ it did it by itself ] ,
41-low voltage [ new batteries 1 yr ago ]
still have tach , incase some one was going to ask.
Now to find out why , too many links in the chain ,
12.36v at all three points on back of alt. [ I know theres 4 but the ground kinda doesn't count and I check it , and the battery connections [ tight and clean , put the anti carode chem. on it with new batt.]
It would help if the connectors were seperate so as to do some testing , but thats got to be prevented .
The factory manual , says to disconnect the batteries , and alt. and put a 150amp meter and volt meter in between , and start eng, and check , then swap the connections for another check ,
This is getting too long , so wheres the short cut ?
How many are putting in an external regulator ?
One of these days I'll get enough mods that there will be no dodge left ,
just a good old Cummins and a bunch of parts I found.

 

To check if it's the alternator or the regulator that's the problem remove the two small wires from the alt and connect a positive and negative jumper from the battery to the two terminals, doesnt matter which is which. Start engine, if the voltage jumps to 14-16 the alternator is fine and the PCM is at fault.

 

Thanks , I wanted to double check that the PCM was not using any other input , becouse I was under the impression that some of the trucks were using the same sensor as tach , not knowing for sure if thats the case , and if so what yrs did or did not .
Like I said earlyer , making some thing that does not need to be , more complicated.

 

I want to get it rite , the 2 small will accept pos or neg with out damage?

 

Thanks Infidel , did that , alt. worked , then went looking for bad connection and fuses , this infront of my fav. rebuilders shop .
Have some resistance at both wires but no batt.+ so figured that the batt. connection was missing , after checking all that I left to go find a wiring diagram ,started the truck and the volt meter is normal and the check eng lite is out so its fixed for now but do not know were that bad thing is , kinda fixed , until I realy need it .