1973 f250 4WD with 360, it has a relatively new battery. The battery wasn’t charging, so I replaced the alternator (it was really old) but the battery continued to die. Next I checked all the fusible links and wiring, finally I replaced the voltage regulator. The regulator fixed everything, it seems. The battery was charging the lights worked. The bat light on the dash even came on when I turned the truck on before starting. After driving about 45 min the bat light came on and when I pulled over and disconnected the battery cable the truck died. Just like before. I did a little research and I know the alternator is a 70 amp, according to carparts.com you can get voltage regulators for different amp ratings. Could the parts place have giving me a 45 amp voltage regulator, and it burned up because I have a 70 amp alternator?

 

One of the worst things a person can do is to remove a battery cable with the engine running.

What tests were done to check the complete charging system before these parts were replaced?

 

Nicholai_reed; If you can find a regulator at a ford dealer you will be better off that one from the local parts stores. If you have an autozone near you you can have them test it for free, if the dealer offers the 100amp regulator one take that one or the best brand that offers a 100amp regulator I have seen ford factory 70amp alternators produce about 105 to 110amps on a bench tester with no problems,no smell,no major heat issues for 20 to 30 seconds, then the customer will bring back the car with the alternator installed on the vehicle & the vehicle will only produce 75 to 78 peak amp output, if you then install a 100amp regulator on it it will put out 90 to 95 peak amps, if you do decide to do this you may want to rewire the out put wire from the alternator to the solenoid, I have seen people just use battery cables to & from to not need to do the guessing game. TURBO TED

 

My real question was, what would make the voltage regulator go out? Also, would replacing it with a higher voltage regulator prevent this from happening agine?

 

Nicholai_reed; The problem could be a ground problem makesure the body has a good ground to it & that the chassis is grounded well also. No the higher amp
regulator will not avoid reliability issues but a bad ground will fry a regulator out. TURBO TED

 

Did you get the battery tested. I have seen batteries cause all kinds of weird problems, including full charge all the time. With charging problems always check the battery first.

 

It was the battery after all. Fortunately it was still under warranty. 1 new battery, and one new regulator and I was good to go. Thanks guys.