I've changed a diesel engine replacing it with a gas engine. It was a 24 volt system, and I changed it to a 12 volt system in the engine compartment. Do I need to change any wiring inside the cab, because I have been having problems with my charging system?
If, by saying you "changed from a 24 volt system to a 12 volt" means you just removed one of the batteries, you probably don't have a complete circuit. Put the other battery back in and see what happens.