I have a 93 D250 diesel and it is not charging? I installed a new altenator and replacted all terminals on the battery? What else could it be? Does anyone have a wiring diagram for that truck? Is there a fusable link somewhere that could be bad thanks! there are 4 wires coming from the atenator ground hot and then a green and blue?
What are the green and blue for?

 

do 93's have a pcm?

 

How's the alt. belt itself?
If it's slipping due to age or corrosion...

 

Check the voltage coming out of the altenator and see if the altenator is putting out correct power. while the truck is running it will be 13.7 or at idel. Next check the power at the battery with the truck at Idel. Then if the bat is low its your wire somewhere. If you cant find it the easyest way is to get a thick wire the same gauge as the bat wire and put it from the alt to the pos. on the bat. Thats the last resort fix.

 

Green and blue most likely go to your voltage regulator. Look for something like this picture on your firewall or inner fender. You can have the VR tested or just try replacing it, they can be had cheap. Make sure the connector on it is ok and snapped on.

 

Run the engine and stick a knife or other metal object on it and check for magnetism, if theres none, the wires might be messed up.
Does your positive cable have two small wires running out? If so does one have a tube like connector,after this connector is a fusible link. Now i knowit would be different, all this info is from a haynes manual, and it doesn't cover diesels.

 

its a brand new belt and the altenator has an internal regulator. i wonder if i could be the belt tensioner?

 

Aaaaah....it's got the VR in the PCM/Computer. Have you pulled the error codes off the PCM yet?
If you come up with a code 41 than you need a new computer as the voltage regulator is part of the computer.




Displaying & Reading Trouble Codes
Accessing Codes
With Check Engine Lamp
To start the function, cycle ignition switch ON-OFF-ON-OFF-ON within 5 seconds and any stored fault code will appear. Check engine lamp will display the code by flashing on and off. There is a short pause between flashes and a longer pause between digits. All codes displayed are 2 digit numbers with a 4 second pause between codes. The lamp will flash until all codes are displayed then 55 (end test) will appear.

 

Thank you so much. I appreciate your time helping me