Hey Guys,
I have a 1998 T-100, 4wd automatic, extended cab. It has 254,000 miles on it and has always been extremely dependable. I've done all the required maintenance for the past 14 years and then some.

For the past couple of years, the voltage has been running high, the alternator runs hot and I smoke an alternator every couple of years. My battery terminals are clean and the frame doesn't have a lot of rust on it considering it's age.

I verified the voltage with a multi meter and it shows high on my compass/voltage Road Pro unit. Tonight it was running 16 to 18 volts.

I assume I have a ground connection somewhere that is rusty or something.

Any ideas???
Thanks,
Winkel

 

install more grounds.

 

It's more likely to be a poor connection on the sense wire that controls alternator charging, it sees low voltage so cranks up the output of the alternator. I don't have any diagrams or experience with that vintage so I can't be much help in troubleshooting it.

 

LOL!

This^^^
Just find schematic, find "S" wire, make sure it is making good connection from battery / fuse block to "S" pin of alternator connector.

 

Maybe and upgrade to a GM one wire setup is in order. More output for stuff.

 

I did a GM one wire conversion on my old 1980, unfortunately it was overcharging so I built my own regulator with some ballast resistors and a relay. I just put different resistors in parallel until I got the voltage I was looking for during normal driving (about 14 volts) and when I turned on the headlights it energized the relay which bypassed the ballast resistors. I was pretty proud of that setup, but it's much better to get the stock setup working right, or at least keep it from looking like a hack job. I did it on a hunting buggy that really didn't matter as long as I knew how to troubleshoot it.

 

Nice for the electrically-savvy, but for those who are not that would be jumping from one fire to the other.