Classic/Antique Car Repair: 1965 impala starting problem, neutral safety switch, starter solenoid

Question
OK well I have and 1965 impala ss with a original 327 in it and I have a little problem their are times I go out to start it and once I turn the key nothing happens it don't even turn the engine over but most of the time I go out to start it it turns just fine.... it's like an 60-40% chance of it doing that....do you think its my starter or just the ignition or the wiring behind it...I am not sure or know to much in that way....

Answer
You'll have to do some detective work here - this type of intermittent problem is very hard to track down.

Step one is to notice, the next time it does this, what the dome light tells you.  When it won't crank, open the door so you can watch the dome light while you turn the key.  If the dome light dims, you know the starter is pulling current, even though it isn't spinning the engine.  If this is what is happening, your problem is a bad starter - you'll have to pull it out and have it rebuilt.  Ask them to install a new solenoid on it at the same time, just to save a future problem.

If when you turn the key and nothing happens, and the dome light does NOT dim, the problem is in the ignition switch or wiring, or in the starter solenoid.   The only way to trouble shoot this is to get yourself a test light, and connect it to the "S" terminal on the starter solenoid.  If the light lights when you turn the key, but the stater doesn't crank the engine, the solenoid is bad.  If it doesn't light, the ignition switch or the wiring from the switch to the starter solenoid is bad. If your car has an automatic transmission, this wire goes through the neutral safety switch, which can also cause your problem.  Next time this happens, jiggle the shift lever while you hold the key in the start position - if you can find a place where it will start, the problem is a bad or misadjusted neutral safety switch.   

So do these simple tests in this order:

If you have an automatic transmission, when it won't crank, jiggle the shift lever. If that makes it start, you've found the problem already - check out the neutral safety switch.  

If you don't have an automatic, or if jiggling the lever doesn't make it start, that still might be the problem but before you tear into that, try the other things I discussed above.

I hope this helps,

Dick