Hello
I've been an occasional reader here for years but I think this is my first post. First off I would like to thank everyone who provides so much help to everyone, I've usually been able to solve any problem just by reading posts here. I bought a nice M1031 from a university auction several years ago and decided this year I would try and make everything right on it. The fire school added a hand throttle lever located under the generator control panel rather than sort out the governor issues. But before I tackle that I came across an interesting question. I installed a battery disconnect a couple years ago between the rear battery positive terminal and the 24 volt buss bar. I noticed that when the switch was off I would get 12 volts on the 24 volt buss. I was wondering if it was just a residual charge from a capacitor or something so I connected a trouble light to the buss and it lit up (half bright). I wondered if I have a problem with the alternators since if I leave the batteries connected they do run down. I guess my first question is, is that normal?
That seems odd to me so I took some measurements. On the driver side alternator with the key off I get 12.5 volts on the + batt terminal, 0 on both the terminals where the brown and red wires would plug in. On the plug end I do have 12.5v on the red wire and 0 on the brown. The passenger alternator (with the + wire off the back battery) has 12.5 volts on the - terminal, 12.5 on the + out (batt) terminal, 12.5 on the terminal where the brown wire connects (with connector unplugged), and 0 on the terminal where the red wire would connect.
Here's a picture of the battery disconnect I installed in the compartment above the welding tanks. I mainly put it back there so I could have a hefty 24 volt connection to run one of those surplus iris (xantrex) 1800 watt inverters I have mounted in the compartment by the generator control panel. I think it's the disconnect from a personnel carrier. I like it because it give me an old style slave receptacle I can use for jump starting generator or running 24v pumps and also has a bulb socket I can plug the trouble light into.
I'd really appreciate some input on the mystery 12 volt / alternator issue so I can move on and document the generator repair and several more projects I have in mind.
I've been an occasional reader here for years but I think this is my first post. First off I would like to thank everyone who provides so much help to everyone, I've usually been able to solve any problem just by reading posts here. I bought a nice M1031 from a university auction several years ago and decided this year I would try and make everything right on it. The fire school added a hand throttle lever located under the generator control panel rather than sort out the governor issues. But before I tackle that I came across an interesting question. I installed a battery disconnect a couple years ago between the rear battery positive terminal and the 24 volt buss bar. I noticed that when the switch was off I would get 12 volts on the 24 volt buss. I was wondering if it was just a residual charge from a capacitor or something so I connected a trouble light to the buss and it lit up (half bright). I wondered if I have a problem with the alternators since if I leave the batteries connected they do run down. I guess my first question is, is that normal?
That seems odd to me so I took some measurements. On the driver side alternator with the key off I get 12.5 volts on the + batt terminal, 0 on both the terminals where the brown and red wires would plug in. On the plug end I do have 12.5v on the red wire and 0 on the brown. The passenger alternator (with the + wire off the back battery) has 12.5 volts on the - terminal, 12.5 on the + out (batt) terminal, 12.5 on the terminal where the brown wire connects (with connector unplugged), and 0 on the terminal where the red wire would connect.
Here's a picture of the battery disconnect I installed in the compartment above the welding tanks. I mainly put it back there so I could have a hefty 24 volt connection to run one of those surplus iris (xantrex) 1800 watt inverters I have mounted in the compartment by the generator control panel. I think it's the disconnect from a personnel carrier. I like it because it give me an old style slave receptacle I can use for jump starting generator or running 24v pumps and also has a bulb socket I can plug the trouble light into.
I'd really appreciate some input on the mystery 12 volt / alternator issue so I can move on and document the generator repair and several more projects I have in mind.
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