Charging issues

[BlueHound]

My 1991 f250 7.3 idi and the issue is that my truck won’t charge unless I jump power to the field wire. After that it charges fine. I do have a broken ground cable and I have replaced my entire charging system.

 

[snicklas]

Have you replaced/checked the voltage regulator on the passenger fender, behind the battery. These alternators use and external regulator, and if it's not telling the alternator to charge, it won't.......

Unless you've done a 3G conversion........ it's internally regulated.

 

[BlueHound]

Yes I have replaced it. As a matter of fact that is where I jump power to the field wire. I also forgot to mention that the battery light never comes on not even when I initially turn the key on, yah know when all the lights should come on.

 

[Macrobb]

And make sure the external regulator is well grounded. That'll definitely cause an issue.

 

[snicklas]

if that light doesn't work, the battery won't charge.......

 

[Macrobb]

Good point. The external regulator actually gets it's initial power supplied via that light, which also limits the current(so don't think you can just eliminate the light and run it straight to power).

If you do 'custom' wiring, you can just find an old taillight bulb or marker, hook that between switched power and the terminal on the voltage regulator. Light should be on with engine off, then go out as soon as the alternator starts making power.

 

[sailorman524]

I went through 3 regulators from Napa just get one good one. Finally switched to 3G and never looked back.

 

[Figor]

What is 3g? I'm having charging problems too. I did a search but 3g is to. Short to perform a search, just get an error saying so.

 

[79jasper]

It's a style of alternator. It uses a internal voltage regulator.
Try "3g swap."

Sent from my SM-G892A using Tapatalk

 

[chris142]

I went through 3 regulators from Napa just get one good one. Finally switched to 3G and never looked back.

This! I fought with regulators till I got a good one. The more expensive ones seemed to be junk. Im running the cheap one from orileys and I carry a spare.

 

[whiteboyslo]

3G Tech Article: https://www.oilburners.net/threads/130-amp-3g-alternator-install.14573/

Better 3G Tech Article: https://www.ford-trucks.com/forums/1156489-how-to-3g-install-for-83-92-idis.html

Mike

 

[OLDBULL8]

3G wiring.

You must be registered for see images attach

 

[laserjock]

if that light doesn't work, the battery won't charge.......

I’m not sure that’s true on a brick nose. It is on an OBS I’m think. I went through this with someone a while back. I think it was Brian working on asmith’s truck.

@IDIoit

 

[tradergem]

I converted my truck to a 3G alternator and now I have a reliable charging system.

 

[Macrobb]

3G wiring.

You must be registered for see images attach

Don't do this, though.
The yellow/white wire should *NOT* be attached to the alternator output terminal. Run that wire all the way over to the fender well solenoid(battery terminal side), or whatever connection point you have that is as close as possible to the battery.
This is the 'voltage sense' wire - If it's attached to the alternator output, any voltage drop due to current being drawn by accessories will result in lower voltage at the battery.
If you put it at the battery, the alternator senses any drops and increases the output voltage to compensate... makes for a very nice, consistent output voltage, no matter the load.

This is also what the factory 3G trucks did, like my '93.