- 249
- 255
- 63
- Location
- Grove, Oklahoma
Hello everyone. I have been trying to diagnose the charging problems on my M1009. I have read the thread about how to check the alternators while they are on the truck, but I don't understand the directions. My alternators don't have the markings discussed in the thread. The charging system hasn’t worked since I purchased this vehicle. I have been all over this truck fixing this and that, but I haven’t yet figured out the how to repair the charging system. Here are some things I believe to be true:
My “Gen 1” dash light never lights up when the key is in the on/run position. I have verified that the light bulb, socket, and ribbon cable on the back of the instrument cluster are FMC.
My “Gen 2” dash light never shuts off when I start the truck or I am driving.
The dash volt meter never goes to green when I am driving.
I can usually start my truck 8 to 10 times before the front battery fails, causing me to charge the front battery.
Here are my assumptions. Please let me know if ANY of my assumptions are false or incorrect:
The LEFT (drivers side – DS) alternator charges the front battery (closest to the grill).
The RIGHT (passenger side – PS) alternator charges the rear battery (closest to the fire wall).
The RIGHT (PS) alternator MUST BE an isolated ground alternator.
The LEFT alternator MAY BE an isolated ground alternator.
I cannot be certain the alternators on my M1009 are factory alternators. I have attached a pic of the stamped information on the body of each alternator. Please let me know if these are “factory” alternators. Can someone please tell me how do I identify an isolated ground alternator?
![Alternators Pic 1.jpg Alternators Pic 1.jpg](https://www.steelsoldiers.com/data/attachments/601/601737-9b6e9021256a3baf1e4da73b6441c1df.jpg)
My “Gen 1” dash light never lights up when the key is in the on/run position. I have verified that the light bulb, socket, and ribbon cable on the back of the instrument cluster are FMC.
My “Gen 2” dash light never shuts off when I start the truck or I am driving.
The dash volt meter never goes to green when I am driving.
I can usually start my truck 8 to 10 times before the front battery fails, causing me to charge the front battery.
Here are my assumptions. Please let me know if ANY of my assumptions are false or incorrect:
The LEFT (drivers side – DS) alternator charges the front battery (closest to the grill).
The RIGHT (passenger side – PS) alternator charges the rear battery (closest to the fire wall).
The RIGHT (PS) alternator MUST BE an isolated ground alternator.
The LEFT alternator MAY BE an isolated ground alternator.
I cannot be certain the alternators on my M1009 are factory alternators. I have attached a pic of the stamped information on the body of each alternator. Please let me know if these are “factory” alternators. Can someone please tell me how do I identify an isolated ground alternator?
![Alternators Pic 1.jpg Alternators Pic 1.jpg](https://www.steelsoldiers.com/data/attachments/601/601737-9b6e9021256a3baf1e4da73b6441c1df.jpg)