CJ ignition switch

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[Bluerocket]

I have an interesting question, my jeep does not shut off with the key anymore.  It continues running until you stall it with the clutch.  Could this somehow be a bad ignition switch do you think?

[mika401]

Interesting seems we have a similar problem!

[Axle]

sounds like the switch?

[BiGdAdDeE]

I'm on board the ignition switch train. 

[Posimoto]

Starter solenoid or ignition switch

With the engine running and key off pull the wire off the “I” terminal of the solenoid. Check the “post” on the “I” terminal and see if its 12v. If there is you need a need starter relay if there isn't voltage you may have an ignition switch problem.


   

[Bluerocket]

Maybe i'm missing something here, the starter acts normal with the key and disengages when you let off the key.   then however with the engine running turning the key to off does not seem to have an effect.  its an electric fuel pump with a TBI 350, which used to turn off with the key.

I can understand bad contacts making something not start, but it seems strange it would keep running?

[mika401]

sounds like your alternator keeps charging with the key removed.  Could be a bad switch, faulty alternator or disconected alternator field wire.  Thats assuming you have a 3 wire alternator right?

[jps4jeep]

CJ's don't have ignitions, they run on hopes and dreams.

Is this the new motor your having issue with?

[Bluerocket]

same motor, i'm giving it one more go before i put a new one in.  starts (but hard) and then wont shut off.

[Axle]

tech day at Bobby's?

[Posimoto]

Starter solenoid or ignition switch

With the engine running and key off pull the wire off the “I” terminal of the solenoid. Check the “post” on the “I” terminal and see if its 12v. If there is you need a need starter relay if there isn't voltage you may have an ignition switch problem.

Hard starts: I would add a voltage drop test as well.

[Bluerocket]

Did a little reading today, and hooked up some hydraulic lines.

It seems that a failed alternator can backfeed the signal wire and cause the engine to see no difference in key on/off.
http://www.jeepforum.com/forum/f8/cj7-engine-wont-turn-off-964617/index2.html

This said, If I charge the battery and disconnect the alternator alltogether It should shut off with the key.

I'll look at voltage drop, but i'll tell you that the starte posative connection gets warm to the touch from cranking.   Battery starter solinoid and cables are all brand new.   I guess i'll play with that some once I get it to shut off with the key.

[mika401]

It sounds more & more like a bad alternator.
I would scrounge for another alternator just to see if it does the same thing.
Sounds like your alternators internal regulator is faulty and the alternator is in charge mode all the time.

[Bluerocket]

I did some testing today now that the engine starts somewhat more easily.

Readings from my "ignition on" terminal on the relay.
Key off engine off = 0 volts
Key on engine off = 13.3 volts
Key on engine on = 13.3 volts
key off engine on = 7.8 volts     <------ that looks like backfeeding to me.  There should be no voltage.

When the engine is running with the key off my ECU and fuel pump are both still live.

I'm going to look up a wiring diagram for the wires to the alt, as one of them goes into the jeep.  ALl the other ones make sense to me and I dont see how they could backfeed.

[mika401]

FYI I added a 10 ohm inline resistance on the load sensing wire and it works perfectly now, no more backfeeding