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A little update: This past Saturday I had alternator tested (twice), it passed, was working as intended. Put back together and started it. Here is what my tester showed ( top photo, was set on 15v DC scale measured at the battery ) Today I hooked up a voltmeter gauge bottom photo ( per instructions, to a switched 12v source at fuse box, used seat belt chime fuse) And it shows the output (both readings at idle).
Last edited by Jeff Wecker; Apr 22, 2021 at 05:24 PM.
Well, it's been a while since my last update, so here goes: Looked over things at least 3 times and studied the wiring diagrams. On a hunch yesterday I drove it over to AutoZone, and had them put my van on their charging system tester. The reman alternator failed the voltage output test. So I go back home, pull it off and exchange it for another one. They bench tested it twice, and it tested out good. So I re install the alternator, and this morning fired it up. Voltmeter still only showing 12 volts. At BAT stud on alt, it's putting out 12.6 volts (same as the battery voltage). I have clean grounds from engine to body, engine to frame. I have good ground wire from alternator to the neg post of battery, and voltage regulator is grounded good.
Was looking at a related thread, and copied this from the thread "Also, for trucks with Gauges, the Stator is left unconnected at the Alternator. Instead, that pin of the VR is used to provide a signal to the Ammeter that's in the Instrument Cluster". So am wondering if I should remove the stator wire from back of alternator, and run to one of the mounting studs, on the back of the ammeter?? It is sounding like the charging excitation circuit is not working. Any thoughts on what to try next?
According to the diagram I posted from a 1981 evtm and if I remember correctly, my 1985 E150 with a 5.0 engine uses a white wire with a black stripe from the stator terminal to the electric choke heater. Maybe your 450 doesn't have an electric choke heater?
According to the diagram I posted from a 1981 evtm and if I remember correctly, my 1985 E150 with a 5.0 engine uses a white wire with a black stripe from the stator terminal to the electric choke heater. Maybe your 450 doesn't have an electric choke heater?
It never had an electric choke carb, the original was a hot air choke. Now running manual choke. Been studying the diagrams too
Well, it's been a while since my last update, so here goes: Looked over things at least 3 times and studied the wiring diagrams. On a hunch yesterday I drove it over to AutoZone, and had them put my van on their charging system tester. The reman alternator failed the voltage output test. So I go back home, pull it off and exchange it for another one. They bench tested it twice, and it tested out good. So I re install the alternator, and this morning fired it up. Voltmeter still only showing 12 volts. At BAT stud on alt, it's putting out 12.6 volts (same as the battery voltage). I have clean grounds from engine to body, engine to frame. I have good ground wire from alternator to the neg post of battery, and voltage regulator is grounded good.
Was looking at a related thread, and copied this from the thread "Also, for trucks with Gauges, the Stator is left unconnected at the Alternator. Instead, that pin of the VR is used to provide a signal to the Ammeter that's in the Instrument Cluster". So am wondering if I should remove the stator wire from back of alternator, and run to one of the mounting studs, on the back of the ammeter?? It is sounding like the charging excitation circuit is not working. Any thoughts on what to try next?
When they bench tested the new alternator, what was the output voltage ?
12.6 seems low. Especially right at the + terminal on the alternator. I would think it would put out at least 13.4 with no load.
if you start the engine, remove all wires from the alternator, whats the reading at the post on the alternator? Just seems strange the best you can get is 12.6 v.
When they bench tested the new alternator, what was the output voltage ?
12.6 seems low. Especially right at the + terminal on the alternator. I would think it would put out at least 13.4 with no load.
if you start the engine, remove all wires from the alternator, whats the reading at the post on the alternator? Just seems strange the best you can get is 12.6 v.
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They did not say, Just that the replacement one passed all tests (output voltage was one of them.) tests ran twice. Have not disconnected the wires yet, rain forecast here thru Tuesday so I won't be able to check this till the rain passes. On mine, the stator wire (white w/ black stripe) runs from alternator, to regulator. My van never had electric choke heater. Will report back after the rain lets up
Now this is interesting and we might be getting somewhere!
Has the instrument cluster ever been changed out?
You siad: "On mine, the stator wire (white w/ black stripe) runs from alternator, to regulator"
I would look at the wiring and see if your van is wired for a light or meter.
The diagram for the 81 shown above is for a van with a ammeter and the white with black stripe going to the electric choke heater and not to the VR. Some models did have an electric choke heater but yours doesn't.
BUT in the 81 EVTM diagram for a van with a warning lamp, the white with black stripe DOES go to the VR..
Here is that diagram
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and here is some information on the carb circuits...Remember this is for a 81 and may or may not be the same as your 82.
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It came with an ammeter as factory, was never messed with by the previous owner. I removed the battery wire, field and stator wires from alternator, 12.5 is what it's putting out.from battery stud.
have you seen this video? https://www.youtube.com/watch?v=KjdaTypqj6o
about 2 minutes Chris talks about jumping out the field wire to make the alternator produce full output.
Looks like he is doing it at the regulator with it still plugged in, from what I understood.
There is an A terminal and F terminal on the VR. you can see them on the diagrams i posted. By jumping out the A and F terminal you bypass the contacts in the VR.
If that fails to get the alternator to produce its full output then you might want to try going directly from the battery positive to the F terminal on the alternator which will bypass all connections on that side of the harness.
I decided to simplify my 73, put a small case G3 alternator, running a 4 gauge charging wire to the battery side of the starter solenoid, and a 4 gauge ground, planning on doing the same to my 89, having an issue finding a ground at the rear of the van on the body, time to start replacing ground wires, body/engine/battery I suspect one is bad or weak, which has me questioning how my van is able to charge the battery like that. BTW I used the same method on a Jeep rather than square away the motorcraft external voltage regulator wiring that had been hacked, used a GM Si alternator in a one wire setup, wont put one on my Fords tho, no plans to contaminate them with bow tie crap.
