took off all battery connections... cleaned them and ran emery cloth on them lightly.. brand new batteries and they tested 11 under a load today.. put on new alt... still does it... when u start it volt guage will hold around 13-14 for minute or two..then it bottoms out.. but truck still runs and fuel pressure and everything stays the same... no effect with lights on or off.. it just graduaaly drains over the period of a day or two.. fml

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oh and thanks all..

 

Does it drain if the truck sets with the key off or only when the engine is running? If it drains with the key off something is shorted and drawing power. If only when it is running it is either not charging or as one of the other posters suggested the intake heater grid could be stuck on. If it is the heater grid you could disconnect the power from the solenoids until you could find out whether it is the solenoid or the temp sensor. If it isn't charging the only thing left in the system is the regulator. Did you check the voltage between the 2 small wires on the Alternator?

 

shpuld have specified better... it doesnt drain it pretty sure its just not charging while running.. didnt test the 2 lil wires no... ehat are they??/

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should*
what*

 

They are the wires to the regulator. One of them is supposed to have 12v all the time. The other controls a partial path to ground to control the alternator output. If you test the voltage between the 2 wires it should be less than 12v but not 0.

 

so they regulate how much the alt puts out??

 

The simple answer is yes. They control a current flow in the rotor that makes the magnetic field. The rotating magnetic field makes electricity in the outer stator windings so by controlling the rotor current you control the output. It is called the field current.

 

Try This

 

thanks DM but thats way to complicated for me... its times like these when i REALLY REALLY miss my old VE truck.. damn electronics.. looks like she's going to the shop..

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Opinions on doing an external voltage regulator or spending the money to fix it factory???

 

I had to put an outside regulator on our 92 d350. It is not very hard to do but I had trouble finding the regulator wire plug. I ended up getting the plug from NAPA. I think it might set a trouble code in the ECM though. It would be the least expensive way to go.

 

can't i just splice into the wires on my factory 2 prong plug on the alt???