Good day 7.3 land! I have a 7.3 related question for my little 5.0 F150...When I sold my 7.3 I kept the Leece-Neville alternator off of it. I recently picked up a 1994 F150 with a 5.0 for a beater while I am rebuilding the 6.0 I acquired. Turns out that the little 302 alternator is the same mounting pad as the 7.3 powerstroke. So I decided to put the LN alternator on that pickup, since it is what I am driving and using to jump start vehicles, tractors, and the like. It bolts up and fits better than it did on the 7.3! No grinding required. I got an alternator pigtail, since that did not match. Just wanting to make sure...the green wire goes to ignition 12+ and the yellow to battery 12+, or am I off? I am concerned, now that it is on, if the higher RPMs of the little gas motor are going to be an issue with this alternator that was designed for a diesel engine. My thought is that it should never be "fully fielded" making max amperage when the engine is at high RPM...it should really only have a high load at lower RPM's. I guess time will tell!

 

RPM has exactly Zero to do with what the voltage regulates at, the same goes for the Amperage Capability.

that alternator might be able to supply 300+ amps, but the regulator will control the voltage that it floats at.

I have a MechMan 320A alternator, and it regulates exactly where it should

this diagram shows the wire colors.






click on this link, to download the files to your PC, not a cellphone.

https://mega.nz/folder/rZAUXJRR#JLHz9tF8NWWwYXrHW1iY-w

 

Ok, so I hooked up terminal 1 to the trucks GR/RD wire, which I believe also goes to "charge indicator", and then directly to battery voltage for the 3 terminal. That appears to be correct. I need to dig out the DVOM and verify charging now.

 

You need to forget the DVM,
get a Power Port plugin and leave it there.





oh, BTW,
I have 3 of those things, and Every One of Them, read 0.2 volts higher than a DVOM shows at the Battery itself.

 

That's pretty high voltage, even if you drop the point 2 volts. I like to see a steady 14, then I'm not worried about boiling the batteries.

 

Well, either I have something wired wrong, or my LN went bad sitting in storage...I need to verify the "charge indicator" situation...the battery light does not even come on for bulb test when the key is on and not running, so maybe the bulb is out and that is causing my issue? I am going to grab the test light and see if that "tricks" it into working.

 

With my Leece Neville, the Charge Indicator did not work either.
and when the Fibreglass packed it up, and the diode pack shorted out,
I replaced it with a MechMan and again;

the Charge Indicator does not work, that is why I put a DVM in the Power Port.
as before, I mentioned, that 3 of those plugin DVM gadjets all read 0.2 volts higher than battery voltage, so this pix indicates 14.41 volts and no, the batteries are NOT boiling water away

 

Well, I took the alternator to Oreilly's, their "plug" for ford alternators is shorted out. Went to Autozone, they did not have the pieces to bolt it down in their tester. So NAPA tomorrow...they are supposed to have an alternator tester. It may be that I don't have a good high output alternator any more! I don't remember if my charge indicator on the 7.3 lit up when the engine was off or not...but it did quit coming on when I was driving down the road!

Also, my charge indicator bulb was burned out, replacing it did nothing, yet. Although I have not bolted everything back up and started the truck since replacing that bulb...maybe maybe!

 

Spitballing here. Does the 1994 F150 use the same alternator excitation as our trucks?

 

I like this question.