1988 gmc 3500 4x4 flatbed truck wont start. new battery ,starter, could it be...

[sum12laughwith]

...a short in the wiring ? worked fine till driven on bumpy dirt road , when i shut it off, it wont start back up . have to pop the clutch to get it running . any body ever hear of such a issue ? thanks

 

[thebax2006]

Easy to diagnose. Take a 12 volt test light and check for power at the starter solenoid small trigger wire. Have a friend hold the key in the start/cranking position while you test it. If no power there, check the electrical part of the ignition switch for a terminal that only gets voltage in the start/crank position. If no power there check for 12 volts going into the switch. If you get power in but no terminal has power in the start/cranking position you have a bad ignition switch. If you do have power out in the start/cranking position the next thing to check is the clutch pedal safety switch. You need power in and power out when the pedal is to the floor. If the switch is good it's time to check the wiring for breaks and/or corrosion.