1990 Dodge Van - Charging System Failure

[Mopar1973Man]

Well yesterday we had our delivery guy Dennis call up with a complete failure. Van died no start and no power. So Stephanie (Boss Lady) calls the local towing service and had him towed to the shop. Sure enough the battery was dead. So I pulled the Cummins up and set the 6 cylinder high idle and charge the battery. Got it fired up and brought it up to the side of the building where I work. We figured the alternator was dead. It just a smaller version of the ND alternators on the Dodge Ram's. So today alternator shows up I get it installed and it was charging good at 14.6 VDC. Sent the Dennis on his way. Less than hour goes by he calls again the CHECK ENGINE light is on. Crap!    Comes back under battery power and sure enough its not charging and tossing a 41 flash code (Field current to high or too low). So now we figure the regulator is dead in the PCM. Guess what? No longer manufactured!  The parts guy told us to hit a wrecking yard. Great!    I ask Lindy do you have a old school Dodge regulator? Sure he said pulls it off the shelf. I jump on the laptop pull up my article on the site for the voltage regulator mod. I gave him the part number for the plug. So Lindy gets it order up. Dennis takes off with Lindy's truck and picks up the part (Pigtail). In the meantime I pull the van in the shop and pull the alternator found the positive field lead (using a test light). Took the negative field terminal folded it back so it no longer used. The grabbed 2 lengths of wire purple and green. Purple went to the positive terminal and the green went to the now empty terminal. Remounted the alternator. Dennis came along with the pigtail trimmed the leads back crimped the two leads purple going to the center/upper post and the green going to the right post. Plug it all in. Fired it up charging a nice 13.6 to 13.7V on the voltage regulator mod.

 

Note: Check your field polarity with the field lead disconnected because if wired to the alternator it will show positive on both terminal. It's a must to test open lead first!

 

So this mod is very generic and will work with any 2 wire field lead alternators without a issue.