I just converted my M1008 to 12V after thinking that my 24V starter went out. I wanted to go to 12V anyways to hook my winch up to the truck. Anyways I get the truck re wired thanks to friend Travis and the new starter does the same thing. It sounds like it is missing the flywheel, but it is engaging and the motor barely moves. The starter sounds like it needs to be shimmed, but after some research I found that these were designed not to be shimmed. I only hooked up one battery when going to 12V (Yellow top optima) and I tested the batteries that were on it before to see if they had enough juice (each had 12V). WTF is going on? I have 10 days to get this fixed before my trip to Moab and I am starting to sweat a little since I need to get this truck started and rolling to test out some stuff on it. Oh ya, the fly wheel has no broken teeth and the block seems fine where the starter mates. How much juice should I be getting at the starter? It's almost like the starter is getting enough power to turn the engine. It can be turned by hand though...... I need help please!!!
Your starter should be getting a direct positive feed from the battery. Have you checked to make sure your motor is grounded well? Do you have a good battery to motor ground? Good motor to frame ground? Is the battery good? Is the starter good? The little wire to the starter that tells the starter to kick over should just be a 12v power supply. Have you used a remote starter to try and start it? If you don't have a remote starter you can hook up a good solid piece or 12 gauge wire and a 15 amp toggle switch from the battery to the starter to use as a remote start. My truck has a toggle switch to activate the starter since the crap inside the column is all wrecked. Harley