No start, Neutral Safety Switch Problem??

[TX75457]

Need help troubleshooting a starting problem on my 1972 C30 with Auto Trans. Had been starting fine until today when I shifted into Drive and while passing the Reverse position the starter kicked in?! Checked wiring, starter, etc. nothing out of order and would not do it every time, but sometimes would kick the starter in while in Reverse. But now it wont do anything while trying to start: turn key on, voltage gauge comes on and dash brake light comes on but starter does not engage. Nothing. Battery is hot. Ran out of daylight and had to leave it at the jobsite overnight. Could it possibly be the Neutral Safety Switch (NSS)? I have always had to exert extra pressure to push the lever into park which may be part of the problem and don't think I have every been able to crank it in Neutral. Appreciate any suggestions where to start...

[davepl]

Backup light circuit was likely trying to power the solenoid, which kicked the starter in, but ultimately blew the backup light fuse because it's not rated for running the starter solenoid.

Have a look at the fuse, let us know.

If my guess is correct, the NSS has broken and the backup light portion of it is sending power out the purple solenoid wire as you go through the Reverse position.

[hugger6933]

You have two plugs under there. [on the NSS] unplug the one that has purple wires and jump them. IF it is the NSS putting a jumper in the purple wires will get you going. Be aware that your truck will now start in ANY gear. It sounds like the tang that sits in the inner shift tube has gotten all worn out of position or the tang itself is broken so no switching action is taking place. Jim

[TX75457]

Thanks Davepl and hugger6933. I'll make up a jumper and take it with me in the morning to bypass the switch. Will let you know how goes.

[TX75457]

Yep, Jumpered the purple wires on the NSS and it cranks just fine. Ordering a new one, Thanks for the help!!

[MagmaJct]

Let me know how difficult it is to replace!

My reverse lights used to be sketchy, now they don't work at all. I also found out one morning I'd started my truck in "D". It started just fine. But with my Carter AFB, I have to feather the throttle a bit for a few seconds before it'll maintain idle on its own.

Imagine the look on my face when the truck lurched a foot or so when I tapped the gas! I found out I can start in any gear!

Regards,
Mike

[TX75457]

Photo shows my old switch on left with broken center tab and generic switch (from local parts store) on right which was suppose to work. It didn't, different center switching tab and mounts, even though the directions mentioned you may only use some of the wiring connectors.

Bought the correct switch online, remounted and adjusted shifter; all is well.

I believe that the column shifting mechanism was out of adjustment and while forcing into park caused the switch to go beyond its limit, hence breaking it.

Not a difficult job to replace but helps if you are a contortionist.

[davepl]

Don't forget to check the fuse for your backup lights! If they blew during this then you have none.