The '58 is now running on a modern alternator replaced about 1.5 years ago. But, for the last month the "Alt" light has been flashing on and off. No problems running the systems and the battery seems to be fully charged. Tested the system yesterday and the alternator is putting out 14.3 volts at idle with no problems. Symptoms are: Lights seem to be pulsing at times, but not always. Alt light flashes now on and off like a turn signal, but not always. Alt light never stays on steady. When I run a load on the system by switching on multiples of load: lights, fans, signals or brake light and radio the light goes out completely. I think regulator needs to be replaced. Probably replace the horn relay too since someone here mentioned it looked "punked". But willing to hear other ideas and suggestions to look at?
I would check the negative cable on the battery carefully and maybe attach a secondary ground to the alternator just to be sure.
There may also be a problem with the alternators diode bridge, based on the fact you said the lights pulsing at times. Anytime that happens, it usually means one diode is bad.
Well, went through the system cleaning up all the terminals and connections. Some corrosion and a little rust removed. Light is off so far and the lights seem steady and solid so fingers crossed while I drive it this next week. Thanks for the help guys.
What alternator did you install? I had a 200 amp PowerMaster that decided to act up when it was only about 5 hours old. It would, for no reason at all, put out up to 27 volts, and then go back to normal. Turned out, it was based on a Taurus alternator, and the voltage regulators on those Ford alternators are known for pulling nonsense like that. After that, if I ever had any problem with voltage, I would not even think twice, but change it as a precaution. It took out a few things on the car, and I' just lucky it didn't catch fire on me.
I have no idea what alternator was provided me when I swapped it out. The engine was a 390FE out of a 1975-79 Ford pickup originally. When I swapped it out two years ago I went to "Battery X-change". They pulled it off the shelf and it's given me no problems since. Drove the car to church and back today with no light flashing. Lights seem steady and bright. I think I fixed it! Cost = NOTHING yet again! I am on a roll here.
How old are your battery wires? If they are more than about 8 or 10 years old, time to start thinking about replacing them. I use 1 gauge, just because I'm odd. LOL
Hmmmm... replaced the Positive wire (post to starter) just a few months ago. Neg/ground wire looks clean and strong and came with the car.
Indeed. The red light does have "GEN" in tiny letters on it. But it's now wired up to an Alternator. The light has been off pretty steady lately. One day last week it started flashing again while I was running errands. But for the last 5 or 6 days... nothing! While I found and cleaned up quite a bit of corrosion from the Regulator electrical connectors, I think it the problem might just be internal. Next repair will be replacing that.
Can you take a pic of your alternator from the side, as well as the voltage regulator, and post them up here? I'm curious as to which specific alternator you have.
