Classic/Antique Car Repair: starting cheve, neutral safety switch, cheve truck

Question
Hello and thank you for the reply.
When you turn the key to start I have the brake light
come on. but the engine will not crank and I do not hear a click from the starter The key to start and nothing.
thanks.
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The text above is a follow-up to ...

-----Question-----
Hello. I have a 1969 cheve truck that will not start, I have good battery and a new starter. It will not turn over it will not do nothing? HELP.
-----Answer-----
Tell me what happens when you turn the key to "Start".  

Do you hear a click from the starter?

Does the engine crank?

Answer
OK, good.

If the truck has automatic transmission, the problem could be right at the neutral safety switch, which is operated by the shift linkage.  If the truck has an automatic transmission, before you go to a lot of trouble, try moving the shift lever while you hold the key in the start position.  If you can find a position where the engine will crank, your problem is a mis-adjusted or failed neutral safety switch.  This switch is operated by the shift lever, and prevents the starter from cranking unless you are in "park" or "Neutral".  It can be either on the side of the transmission, or at the base of the steering column (if you have a 1/2 ton), or somewhere where it can be operated by moving the shift lever.

If the truck has a clutch pedal, you'll need to get a test light or a volt meter and check the voltage on the "S" terminal at the back of your ignition switch when the key is all the way over on the "start" position.  If the test light comes on, or the voltage jumps up to 12 volts (approximately, the exact value isn't important), then we know your ignition switch is NOT the problem.  If it does not jump up to 12 volts when you twist the key, the ignition switch has failed.  NAPA stocks these, - just take in the old one and they will match it up.

(Just in case you haven't used a test light or meter before, put the black clip lead on something that you KNOW is grounded, for instance a bare metal part that is bolted to the car body or dashboard metal.  Then put the test probe or red lead on the terminal you want to test.  On the meter, put the selector knob on the + DC VOLTS position, the range where 12 volts will be somewhere around the middle of the needle's range so you can easily see it.)



If the ignition switch checks out OK, move your test meter or test light to the other end of the same wire, which you will find on the "S" terminal of the starter solenoid - it is one of the two small terminals on the top of the starter (assuming you have a V8 engine - you didn't say), but for any engine, the terminal we care about will have a letter S next to it.  Have a helper twist the key to "Start" while you test that terminal - it should also show 12 volts (or the test light should light) when you try to crank the engine.  If it does, but the starter does not crank, your solenoid is bad.  If it does not, we know the wire from the ignition switch to the starter is bad, or has come loose somewhere (double check the wiring to make sure the connection is good).  

To prove this is the problem, take a separate wire and temporarily touch one end to the + terminal of the battery and the other end of the wire to the "S" terminal on the starter. BE CAREFUL, THE ENGINE MIGHT CRANK NOW, SO MAKE SURE IT IS NOT IN GEAR - YOU ARE BYPASSING THE NEUTRAL SAFETY SWITCH (IF THE TRUCK HAS AN AUTOMATIC TRANSMISSION) AND THE TRUCK COULD START AND RUN OVER YOU!!!!



If that makes it crank, just follow the wire from the ignition switch to the starter until you find the problem.

Dick