On our 89 F250 with a 7.3 diesel, We have a charging problem. We have replaced the batteries, the alternator, and the voltage regulator.l But still will not charge. Everything inside tha cab is manual so no drain on windows, or locks. I have checked it for charging at the batteries and nothing. I am stumped. If anyone has an idea of what could be wrong or there is a post out there with this problem , please let me know.
Thank you
Susan

 

Are you getting voltage from the sensing wire connectors (I assume it is a two wire connector)? Have you checked all of the ground wires?

Have you checked the cable from the alternator to the passenger battery? IIRC it may have a fusible link in it.

Check out this link for some ideas.

https://www.justanswer.com/ford/3ovy...iot-light.html

 

we have new.cables on both batteries. where would the fusable like be located, exactly

 

If you haven't found the problem yet , you might consider trying the following.

If, your voltage regulator has 4 wires at the plug, unplug that plug and connect a jumper connecting the "A" & "F" of the plug. Now start the vehicle , If you are getting more than 12 volts at the battery , the regulator or the wiring to the regulator is defective.

If you are getting no voltage change , the alternator or wiring or connection from the alt to reg is defective.

Just because "another" regulator or alternator has been installed is no guarantee they are good, some rebuilt alternators come out of the box defective also.
Pay extra attention to the connections at the plug that goes on to the alt.

 

We are going to try this next. We have power to the regulator but cannot find the fusable links. We think they were taken out and direct wired.