i have a 1995 dodge ram 12v Cummins with 274983 miles on it i put a new heater core in a few days ago and reconnected everything and started the truck and i had no tach and alternator aint charging and the check engine light aint coming on when u turn the key on for its 3 seconds and the bulb is good so i read on here and i got a new engine speed sensor put it on gaped it and still the same thing can someone please help me out thank you

 

Not too familiar with the '95's, but it almost sounds to me like you may have forgotten a connection in the dash cluster, possibly a ground?

 

no i checked all that pulled it all back apart and according to my dodge book there is only 3 grounds down there and they are all connected everything works but the tachometer it wont charger and the check engine light the oil fuel and speedometer works i dont know about the temp cause i aint let it run long enough to get warm

 

As I said, I am not too familiar with the 12 valve engines as much, but the alternator is controlled by the PCM I believe, and if it doesn't see any RPM's it won't ask the alternator to charge.
Did you disconnect the batteries when you initially pulled the dash? I can only think of maybe a PCM issue, or possibly a crank position sensor issue. Other than that I am out of ideas.
Hopefully someone else with a bit more experience with that model year will chime in soon...

 

Bingo!

 

Actually he said he did put a new ESS on it and has set the gap . (op)

I would suggest check your plug ins at the PCM because it does not seem to know the engine is running so no tach reading and alternator not charging .
Also check that ESS wiring.

Mishkaya - there is no crank position sensor on a 95 12 valve just the engine speed sensor (ESS) on the engine front triggered from the damper .

 

i have checked all that the back of the insturment cluster has no tach singal from the pcm so im guessing a bad pcm and i did disconnect my batterys when i pulled the dash im going to see if i can run everything and skip the pcm and leave it out of everything

 

The wiring from the crank sensor often gets chafed. Check it carefully before you decide the PCM is bad.

Also try setting the gap around 0.040, a little tight is sometimes works better.

 

on the wiring how could it go bad from me just putting a heater core in? cause everything was working right before i did it you get what i mean?

 

Not saying the two things are related. I don't know enough about the 2nd gens to comment on how doing a heater core could affect the wiring.

 

Have a close look at the drivers side battery negative terminal, PCM grounds here. I'm betting the terminal is corroded , broken or something like that.

 

nope i just put new cables ends and batterys in less than 2 months ago but again why would it do this after doing a heater core

 

Did you hookup all the ground wires at that negative post? Bad crimp if new terminals were used? What may have done it is moving the pcm to get the heater plenum nuts, could you have pulled a pin back in the connector on the PCM?

 

its not that i didn't pull the pcm that hard and the battery cables are soldered so ya also it would of done it way before now if that was it on the ground im wondering if its a fusible link anyways thanks for bur help cause i dont c how it could be a wire from behind the dash

 

theres a 130-ish amp fuse directly on the main power line in the fusebox underhood. if that went open you'll get no charging as well as some other issues.

could be just coincidence. check that big fuse and everything else. before going straight to bad ECM>