2003 Ford E450 7.3 L PowerStroke->I am trying to diagnose an electrical issue. The vehicle can be jump started, but when the cables are removed, the dash gauge voltmeter, as well as directly testing volts at battery shows a slow voltage drop, until the engine fails.It has a single 200 amp Penntex alternator, with dual new Interstate batteries. The alternator was just today bench tested at 15.0 volts.Where is the voltage regulator located on this vehicle? Some blogs say internal to alternator, while some say external, on fender or firewall. Conway
Country: United StatesMake: FordModel: E450Year: 2003Engine: 7.3 L
Hello I'm Chris
Bench testing an alternator just means it works in a perfect environment not when hot under the hood and with vehicle voltages to it and not converters providing simulated voltages.
So far it is acting like a faulty alternator or a missing input to the alternator not triggering the alternator to make voltage.
Use the below Ford wire diagram and tests to find out which input at the alternator is not registering correct to get an output of 13-15.
Thanks for pressing accept, Chris
16 years experience with Ford.
Chris,Is the voltage regulator external or internal in this type of vehicle?Is it possible to send you a picture of the regulator?Conway
Sorry I forgot to type that, its part of the alternator/generator. The PCM only controls the voltage when you have dual alternators. The regulator should only be changed with a new or refurbished alternator.
Yes you can send pics, but I have seen plenty of alternators with the regulator mounted on them
So in a single alternator system, the voltage regulator should be bolted directly to the alternator, or is it internal where I cannot see it?Conway
There are 2 ways to answer your question. There are vehicles that all of the amp charge is controlled by the alternator, and there are vehicles where as the PCM (computer) tells the alternator what to do. These 2 setups are what are now referred to as internal or external voltage regulators.
Your asking if the regulator is inside the alternator unseen or mounted on the outside of the alternator visible. I went to Penntex since your not running an OEM alternator. They say there is a remote mounted regulator since they do not put regulators on there alternators. So it is not going to be setup like the Ford diagrams I sent.
Read the section which begins with NOTE.
Should the regulator have a (+) lead that runs directly to the alternator?
There should be a battery positive cable to the regulator.
Did you find a externally mounted regulator like Penntex mentioned?
I found it. It is mounted under the passenger side dash, accessed from within passenger compartment.The 4 pin connector had pulled loose. I have to re-install the alternator, but I assume that it will then function correctly.You have been a great help.May you feels Christ's blessing in your life today,Conway Cox
Glad I could help.