Engine/Transmission (1994 - 1998) 96 12 valve cummins delayed shut down

[DavidMCGarage]

So I work in a shop as a mechanic and every now and again I get stumped. I currently have a 1996 dodge ram 2500 with the 12 valve cummins with a laundry list of repairs. The one that is stumping us right now is that the truck will run for roughly 30 seconds after taking the key out. I have replaced the fuel overflow valve to fix the hard starting. Any ideas will be much appreciated.

 

[BigPapa]

Got to be the shutdown solenoid or the relay hanging.

Put a voltmeter on the green wire connected to the solenoid and see if the voltage goes away when you turn the key off. If it does then your solenoid is hanging, possibly dry, rusty linkage, a deteriorated boot binding things up, debris or corrosion in the solenoid bore, or possibly even a broken spring. If the boot is torn at all, remove it totally from the solenoid. Mine has not had a boot on it for the past 10 years and 300K miles.

If the voltage is still present after you turn the key off I would replace the relay and test again.

If the voltage is still present after replacing the relay I'd look at the ignition switch.

 

[GAmes]

Could be bad starter contacts also. http://www.fostertruck.com/faqs/

 

[DavidMCGarage]

Got to be the shutdown solenoid or the relay hanging.

Put a voltmeter on the green wire connected to the solenoid and see if the voltage goes away when you turn the key off. If it does then your solenoid is hanging, possibly dry, rusty linkage, a deteriorated boot binding things up, debris or corrosion in the solenoid bore, or possibly even a broken spring. If the boot is torn at all, remove it totally from the solenoid. Mine has not had a boot on it for the past 10 years and 300K miles.

If the voltage is still present after you turn the key off I would replace the relay and test again.

If the voltage is still present after replacing the relay I'd look at the ignition switch.

Thanks, Ill be testing all of that on Monday morning and ill let you know.