I have a 1986 Chevy C6500 firetruck with a 427 tall deck. After getting up to temperature The truck will randomly turn off and all of the gauges will drop until you switch the ignition to the off position and then back on, the truck will then backfire and the engine restarts. I have replaced the ignition, distributor module, coil, cap and rotor but that has not fixed the problem. The truck is also wired with a battery cutoff switch.

any ideas on this would be greatly appreciated.

 

Hello friends, have you tried to use diagnostic tools to detect what is wrong with your car? I hope I can help you.

 

It sounds like you have an electrical issue causing the truck to shut off. Since you’ve already replaced the ignition components, the problem could be related to the wiring or a bad ground connection. Here are a few things to check:

1. **Battery Cutoff Switch**: Check the wiring and connections around the battery cutoff switch. A loose or corroded connection could be cutting power to the ignition.

2. **Wiring**: Look for damaged or worn wires that could cause intermittent power loss. Pay attention to wires running from the ignition switch to the engine.

3. **Ground Connections**: Check all the ground connections, especially the ones from the engine to the chassis. A poor ground could cause the gauges to drop and the engine to cut out.

4. **Ignition Switch**: Even though you replaced the ignition system, the ignition switch itself could be faulty or have a bad connection.

Try checking these areas and see if it helps.