I have a new to me M1010 and am trying to figure out some parts that arent working. The truck has been somewhat electrically converted, where the DUVAC has been removed and one of the alternators swapped for a 12V alternator, which is hooked up to the 12V bus. The lower 12V alternator is currently not working.
Ive tried disconnecting both alternators, then hooking them up one by one. Hooking up the 24V alternator gives me a voltage of 28V on the pos terminal on the upper battery, so that alternator is working. With that disconnected and and then connecting the 12V alternator, the voltage at the pos terminal of the lower battery (so 12V) is not increasing at all. Holding at 12.5 V. So that is how I concluded that one is not working.
I dont know if it is improperly connected, or if its just broken. There have been several things wired wrong on this truck from the previous owner, so I am not discounting that. However it seems that there are only two terminals on the alternator that would be used (+12 and ground), and they are connected properly. It is a prestolite a0012800lc and looking at some diagrams it only notes the positive and negative port, an AC port, and then some test ports (full field access). So I dont think there is a terminal that is supposed to be pulled up to 12V to enable the alternator (this is the case on the 24V alternator). Voltage at the positive terminal of the 12V alternator without the wire connected is a little over 1V. All of this makes me think it is just broken.
If anyone knows anything about these alternators and If I am doing anything wrong that would be helpful.
Ive tried disconnecting both alternators, then hooking them up one by one. Hooking up the 24V alternator gives me a voltage of 28V on the pos terminal on the upper battery, so that alternator is working. With that disconnected and and then connecting the 12V alternator, the voltage at the pos terminal of the lower battery (so 12V) is not increasing at all. Holding at 12.5 V. So that is how I concluded that one is not working.
I dont know if it is improperly connected, or if its just broken. There have been several things wired wrong on this truck from the previous owner, so I am not discounting that. However it seems that there are only two terminals on the alternator that would be used (+12 and ground), and they are connected properly. It is a prestolite a0012800lc and looking at some diagrams it only notes the positive and negative port, an AC port, and then some test ports (full field access). So I dont think there is a terminal that is supposed to be pulled up to 12V to enable the alternator (this is the case on the 24V alternator). Voltage at the positive terminal of the 12V alternator without the wire connected is a little over 1V. All of this makes me think it is just broken.
If anyone knows anything about these alternators and If I am doing anything wrong that would be helpful.
