1970 Ignition Switch

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dd70340

dd70340

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I have a 1970 Dodge Dart 340 that has a rallye dash and an in dash tach I got from Classic Industries. I thought I was having a problem with the tach because the needle doesn't move when I start the car, however it does move about 10 seconds or longer after the car starts running. Yesterday I noticed the ignition lock only goes about half way back to the start position when I turn the key and let it go. At that point the tach doesn't move, however when I move the key to the run position the tach springs to life. The key moves easily into and out of the cylinder and turns freely without binding. The only problem is the cylinder doesn't spring back to the run position after turning it to the start position and letting it go. Does this sound like a problem with the ignition lock cylinder or could it be a problem with the ignition switch?

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On mine the lock has no or very little spring.
and the main springing action is in the switch

my ignition lock and switch is most definitely not the same as yours.
but it seems to follow a pattern used on many cars

i.e the "drive" to drive it back to RUN from Start is applied in the switch

Mopar being mopar, with its occasionally different ways, i can't say if this is correct for yours all i can tell you is what i have encountered

i.e if you take out the lock id expect it to turn freely with the key to all positions and stay there.
off the bottom of the lock will be a CAM that drives the switch and the switch will most likley have a set if dentents and a spring in it, to spring from Start to Run and the detent balls will keep it in Run until you switch it of ACC or OFF.

repair of the switch may prove better than a new switch. they can usually be un-crimped to find out what is wrong and then be crimped or drilled and pinned back togther.

Dave
 
Dave,

Thanks for your comments. I suspect the problem is with the switch and I want to see if anybody had a similar problem with a 70 and later car. I'm hoping it's possible to fix the problem without taking the column apart since as you can see in this FABO article you have to take a lot of parts off to get to the switch How To Install an Ignition Switch in 1970 Dodge Dart.
 
The return spring from the start position back to the run position is inside the ignition switch. If it works fine otherwise, just remember to help it back to the run position. If there are other issues with the switch (check the connector by the column under the dash for any melted wires/connector), start looking for a replacement. Not sure who carries a good quality replacement these days. You may have to scare up a good used one.
 
Do the ignition switches get sticky from dirt and just need to be cleaned in order to function properly? Except for not going to the run position after starting my switch is working fine.
 
It's a sealed unit, so, the only lubing you can do is around the shaft. It's possible that might help. I'd try some spray lithium grease and cross your fingers.
 
yeah if you take it apart. speaking from experience with a different switch, the crimping looses its "crimp"
to reassemble i ended up using carb jet drill to drill through case into switch base and pinning the base in with the screws you use on spectacles/ sun glasses with some epoxy over the ends to keep em in

did that 10 years ago... still working

i have the beauty of a 2 year only, not, and never will be re-manufactured, switch. i ended up plastic printing parts for it.

Dave
 
I took my steering column apart yesterday to work on the ignition switch and found the shaft was dirty. The ignition switch spring couldn't get the shaft to fully rotate so I cleaned the switch with WD40 then sprayed the shaft with lithium grease and now the shaft fully rotates. I also cleaned the lock cylinder and lubricated it with graphite. The ignition now works properly. Thanks for your help guys.

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