1993 1st gen, alternator not charging

[slomoe]

alt stopped charging, replaced alt, still not putting out. I have power to the alt. The battery cable to alt is good. I am told a crank sensor will cause a no charge situation. But I can't find a crank sensor. This truck was built with 46RH trannie, but it now has an NV4500. Was also told the PCM can cause a no charge situation. But where in the heck is the PCM? Not anywhere near the battery, not under the dash, not under the seat. And this 1993 D250 model is supposed to have an external voltage regulator. But I can't find one of those either.
Not a good day!

 

[dodgenstein]

PCM should be inside the driver side fender tucked behind battery. Voltage regulator is inside the PCM. Crank sensor is above the harmonic balancer, just left of straight up (facing motor). There is a plug immediately in front of the front valve cover and slightly down, that goes to crank sensor. be sure it is clean and connected.

 

[slomoe]

PCM should be inside the driver side fender tucked behind battery. Voltage regulator is inside the PCM. Crank sensor is above the harmonic balancer, just left of straight up (facing motor). There is a plug immediately in front of the front valve cover and slightly down, that goes to crank sensor. be sure it is clean and connected.

Thanks Dodgenstein. I'll check it out in the morning. I have a crank sensor coming tomorrow.

 

[DaWord2011]

Just to let you know, if there is an issue with the PCM causing a non-charging situation, you can also bypass this and make your alternator a 2 wire alternator by installing an IN8315 onto the stock alternator. There are several write-ups on the procedure if you can't track down the issue.