Hello everyone So the other day I went and started my backhoe and noticed that my tach and hour meter aren't working and they were the last time I ran it. So I started to do some research on here and found out that the alternator light should illuminate when the key is turned on and not running and mine is not. So I removed the instrument cluster and the bulb looked a little burnt so I replaced it. That did not fix it. So I did a test with my multimeter and am only getting 12.4v at the batteries and 12 something off the alternator while the machine is running. Could my alternator be bad? I would think that I should get a higher number off the alternator. Just trying to eliminate wasting funds on an alternator.
I also ran a jumper from the battery to the small post and the numbers didnt change.
Tighten all connections first. Maybe the regulator is bad. New brushes are part of the replacement. It is on rear of the alternator. Cheap and very easy to replace. See the link for an example. https://www.ebay.com/itm/VOLTAGE-RE...750929?hash=item3f6fb01751:g:nPgAAOSwux5YMejG
Are these pretty common to fail?
this is 20-30 years old right? yes alternators are pretty common to fail at any age. Definitely fix the alternator before looking for anything else. Test the alternator before replacing it. If the alternator is the original, I'd rebuild it or get it rebuilt, don't trade it in as a core for a cheapo import if you can avoid it. Case didn't make alternators, so it should be easy enough to figure out what brand it is and how to rebuild it. The battery voltage should be over 13 running, and the alternator should be the same at the big wire. Alternators need power to turn them on in one of the smaller wires. Even a new good alternator won't work if it doesn't have the excite voltage from the ignition switch.
Delmer what would be a good way to test to see if there is a short in the excite side of it? I tried the jumper from the hot on battery to the small post and the numbers didnt change? I read on here somewhere to try that jumper I just mentioned.
It wouldn't be a short exactly, but people say short to mean a lot of things electrically. If you have battery voltage on all of the terminals when it's running, (except the tachometer terminal that will have AC Voltage present) but the voltage is not above 13, then take the alternator off and get it tested either at local rebuilder who will get yours back to you, or at an auto parts place if you're going to fix it yourself (or get a cheap replacement). If you don't have battery voltage on all but one of the alternator terminals then jumper from the big Bat+ terminal to see if it will start charging. Don't jumper to a ground terminal, that is a bolt with no insulator that is for a ground wire to the alternator case.
Ok I guess I'll start with getting the alternator checked somewhere local here. I believe there is an older guy in town that redoes starters and alternators.