Key won't start the car but a screwdriver will!

One out of every 40-50 fire-ups the road runner will not turn over. When I turn the key I get absolutely nothing. No clicking, no whirling, no sound what-so-ever. So I've learned that if I get a screwdriver and bump the starter by connecting the power lead to the solenoid at the starter the engine will then turn over just fine using the key.

So why does happen?

If it's an automatic try starting it in neutral. Your neutral safety switch may not be activated. Your shift linkage could need adjustment.

The starter relay could be bad.
The netural switch or wire could be bad. If stick, does it have a clutch in switch?
The YELLOW wire from the Ignition switch to the starter relay could be bad. This could be in the bulkhead connector plug or at the ignition switch.

This is where a simple 12 volt test light is a good thing to have. It has a clamp on the long wire and a sharp probe tip to check connectors.

Good thought but it is a four speed.

I beat the heck out of the relay but that didn't seem to help. I may try replacing it, they're not too expensive.

I guess I could see a bad connection being the culprit but I'm surprised that bumping the solenoid would fix the problem every time.

You are bypassing the relays inside contacts when you screwdriver the two lugs on the relay.

Some 4 speed cars has a switch on the clutch pedal that goes the the neutral switch of a starter relay too.

Tri-Cities is 150 miles too far for me to drop over to help, sorry.

If you had that test light I posted above I can tell you how to test each section, one at a time. Just throwing a starter relay on may fix it but there are other things to test too.

I had a 4-speed '68 B-body that from time to time had the same thing happen.
Wiggling the yellow wire at the relay would "fix" it for awhile.
Found the post was kinda loose.
Replaced the relay, and no problems since.

The Auto and stick shift relays are different. RockRuto has repop ones.

I do have one of the old test lights and can test the system. The next time it happens I'll chase it down with the test light. Of course, it usually does it when I'm in a parking lot somewhere not when I'm home!

Thanks for the good advice.

With it happening 1 out of 50 starts, maybe just throw a new relay on. Then if it does it again you can chase it.

STANDARD MOTOR PRODUCTS SR106 $16.22 from RockAuto, $22.94 with shipping and Govenor's share.

Yep, that's the way to go. Thanks.

That changed by the 70 where manuals used the same than autos too ( or it was 69? Can't recall ), needing to press the clutch pedal

Yes, S4 is a ground.
In a pinch, the AT relay just needs a short ground wire from there to a mounting bolt to work on a 4-speed car.
Also a clever way to rig up an anti-theft device...