Starting Issues

[just_a_guy84]

Hello all, I have a 1977 GMC sierra with some starting issues. It will start cold however when it is hot it will not start. I have done a few things to help alleviate the issue with less than positive results. thus far I have replaced the starter, all cables, cleaned the ground connection and mounted it to the frame rail and I have mounted a remote solenoid on the firewall. After the truck has run for a while to normal operating temperature it will turn over very slowly and the starter will stop suddenly with a heavy and awful clunk, I should note that I have checked the flywheel and starter and the teeth are ok. I will also note that there is a single wire (10 gauge) that runs from the firewall to the block that gets exceptionally hot and has melted the insulation. This is driving me crazy as I feel that I have tried every avenue. thanks, Aaron

[mcreyaufmiller]

Aaron,

 

If the insulation has melted on the wire, then it is overdrawing amperage. A 10ga wire is good for 30 amps. There are 2 things that could be wrong here, first, the wire could be corroded and causing the amp load to go up, or the wire is under sized for the application. If this wire is a ground wire, then you have a grounding problem. Make sure the block and the frame are both grounded to the battery.