[Hotrodjohn71]

Hi group.
I'm having an occasional no-click no-crank issue on the stock 326 starter in our 67 firebird.

Good battery, 12.6v (engine off), new ignition switch, and new wiring harness for the engine compartment, but old starter.

How do you isolate the solenoid to test it and what numbers do you need to see?

Most of the time the car starts flawlessly, but sometimes, I get no click, no crank, and looking at the in-dash warning lights when attempting to crank (during the no click, no crank) I see them dim when I turn the key.

This makes me think the solenoid is drawing current but (for some reason) not enough to cause the solenoid activation and startup.

So I went under the car and connected a jumper from the S terminal and ran that wire over by the battery but just left it hanging.

Next time I got the no click, no crank, I jumped out and connected that jumper to the battery and it started up.

[Hotrodjohn71]

One thing I forgot to mention.

I believe I troubleshot the neutral safety switch by going from park to reverse while the issue was occurring and I could see the dimming of the dash lights would stop when I shifted into reverse (opening the circuit).

This seems to indicate that the switch was working because when in park, the lights dimmed again indicating a draw on the system.

[Goatracer1]

If you are jumping directly to the starter and it cranks it can't be the starter or the solenoid. If this is an auto trans car check the neutral safety switch. When it doesn't crank jump the 2 purple wires at the switch. If it is a manual trans there is usually a jumper at the harness where the neutral safety switch should be. Have someone help you and using a volt meter check for full voltage at the purple wire. For either type trans you should have battery voltage at all points on the purple wire when in the start position.

[Hotrodjohn71]

Thank you!
I'm going to do some voltage testing.

[gto4ben]

I had a problem like yours and performed a voltage drop signal trace using an external 1 Amp power supply in place of the battery. This was so the solenoid would not move when turning the key to start and I can get a steady reading. I discovered that the purple wire crimps at teh neutral safety switch were the source of excessive voltage drop. Here are the measurements I made wrt ground, both before and after I soldered the crimps.

[Hotrodjohn71]

I had a couple of minutes today to analyze my issue.
I got under the car and disconnected the purple 'S' wire at the starter and connected it to my volt meter. I thought I might as well begin at the end of the circuit.
I was getting about 12.5v with the key in the start position. While in start, I shifted out of park and down the selector several times and each time I went back to. Park or Neutral, the voltage never deviated or went dow.n.

[gto4ben]

In order to get a voltage drop, you need an electrical load at the end of the wire you disconnected. Without the load, it'll act like a probe and you'll just measure the battery voltage. For example, If you have a 15 ohm, 10W resistor lying around, connect it to the disconnected wire and the other end to ground, then repeat your measurement.

[Jack Gifford]

Also look for a possible sometimes-short to ground of the wire to the S terminal- frayed wire, etc.

[Hotrodjohn71]

Thank you for the great advice.
Is it common to have shorted wires in the steel tube wire protector (on the back of the block at the head) where the starter wires run through?