On our 89 F250 with a 7.3 diesel, We have a charging problem. We have replaced the batteries, the alternator, and the voltage regulator.l But still will not charge. Everything inside tha cab is manual so no drain on windows, or locks. I have checked it for charging at the batteries and nothing. I am stumped. If anyone has an idea of what could be wrong or there is a post out there with this problem , please let me know.
Thank you
Susan

 

Blown fuse Link on the B+ / A Regulator Line, is the first thing that comes to mind.

Is the charge light ON by any chance ?

Here is a wiring diagram for it ... note where the Fuse links are..

 

Yeah sounds like the regulator isn't getting power, or the regulator isn't making it over to the alternator.

I believe It's a greenish wire that's the key on for the regulator, yellow is all time hot.

Also make sure you plugged in that little plug on the side of the alternator. Sometimes they get corroded too.

 

Corrosion X is my Go To for connectors Just because parts are new doesn't mean they are not defective.... but as DarkOverCast says could be bad connections.

Thing is you can check an Alternator by Full Fielding it ... Just excite the Field Windings and measure the output Voltage.... this Bypasses the Regulator.

 

we took off the alternator and the regulator and took them into NAPA. They checked out to be good. I will check the fusable link next and double check the plug going into the regulator

 

Charge light is not on

 

We have power to the regulator, but not sure if the previous owner took out the fusable links. We are still trying to find them.

 

they terminate at the starter Relay that is near the Passenger side Battery.

you should have Battery Voltage On the B+ terminal of the Alternator and also Battery Voltage on terminal A of the Regulator with the Key OFF and Engine not running.

Measure that Voltage and write it down.

Then with the Vehicle Running you should see a minimum of 13.8 Volts.

 

The first picture is the alternater and the second picture is the regulater. We do not have the wires that you show in your wireing diagram. . We have the 7.3 diesel . We also do not have the fueable links. They were removed. So how do I proceed with the wires when they are different from your diagram.

 

here is a nice Web page with a 1989 Ford charging system, while it is not Diesel it is Same difference......

https://www.w8ji.com/battery_and_charging_system.htm

 

The wiring Diagram I posted for you is the 1989 F250 7.3L Diesel OEM wiring diagram according to FORD
Looking at your Pictures it looks like in Fact you do have the same color wires per the Diagram... IF the Fuse links are removed then fine, I'm sure the Original Owner just hooked the wires straight to the Starter Relay then.