CUCV won't turn off with key

[ArmyVet77]

Hi Guys!
I hope someone might have some good advice. My CUCV won't turn off with the key. I have to pinch fuel supply line to the fuel pump to turn it off.
I have checked the ground bus near the parking brake, cleaned and reattached it with a fresh bare metal surface. I have replaced the ignition switch at the base of the steering column. I replaced the ignition cylinder. While in the column I put in a new turn signal switch. All lights, signals, accessories work as they should.
I checked for voltage at fuel solenoid when off and its 0V. However I am no electrical guru but when running its 0V also, I assumed it would be 12V running?
Any ideas? Thanks for the help!

 

[Westech]

Sounds like a stuck fuel shut off. Replace that and find your voltage supply issue.

 

[ArmyVet77]

Thanks. I fixed voltage issue. But the problem is still there. Waiting on a new solenoid, will post the results when I get the part in.

 

[dmetalmiki]

Curious, Are these deisels or petrol motors? Because a gas motor only has to break a circuit to stop. No volts no go. But a deisel Should have 12 volts to a fuel solonoid or pump. Break the circuit no go Unless the feul shut off solonoid valve sticks open. (0 volts normally closed). just my 1/2 penn'eth

 

[cucvrus]

These are 6.2 Detroit diesel engines.

 

[ArmyVet77]

Ok, received the solenoid and finally got a chance to work the CUCV. Pulled top of injection pump to look at solenoid. The solenoid worked when 12V put to it but it has a sticky spot so it didn't have full movement. Installed the new one and it shuts off as it should. Thanks for everyone's input.

 

[acesneights1]

Glad you found it. I had a civvy one that did the same thing. Drove me nuts. I had no juice at the Sol wire but if I unplugged it the truck would die. I even took the truck to church and threw Holy water on it because I was sure it was possesed.
There was something wrong inside the ignition switch and it was allowing less than 1v to get by even when in off position and that was enough to hold the sol open .It took an actual voltmeter not a test light to find the problem.

 

[MarcusOReallyus]

It took an actual voltmeter not a test light to find the problem.

This is a very important point for anyone doing electrical troubleshooting.

Sometimes, a voltmeter will show a problem that a test light has missed. Sometimes, a test light will show a problem that a voltmeter has missed.


This is because a test light puts a load on a circuit, which a voltmeter does not. For some problems, that load masks a problem. For others, it reveals the problem.

You need BOTH in your toolkit.