Electrical Problem / Insanity, Starter issue Options

[jsaum]

Before I go totally insane I'm hoping someone can help me through trouble shooting a problem with the ignition switch not actuating the starter. First a little information, I have a late model year 1972 1.7 with the fuel injection removed and a carburetor installed. After six months of working on the car I've finally gotten to the point where I have installed the motor with a new starter The car has been apart for 12 years sitting in the garage. First the starter failed to work when I tried to turn it over. Thinking the new starter was bad I took it off and had it tested this morning at the auto parts store it works fine. I also had the battery checked and it is good as well.

I put the starter back in and it worked four or five times so I thought it was fixed. I then hooked up the fuel line and went to try and start it and the starter wouldn't work again!#@%###. I can jump it across the positive battery cable to the solenoid and it works. I have 12 volts on the yellow wire to the started solenoid when it is disconnected and 8.5 volts when it is connected when the key is turned. I have checked the relay board at pin # 6 and I have 12 volts there when the key is turned with the connector off. I ran a jumper wire to the solenoid from pin# 6 on the relay board and the voltage goes down to 8.5 when the key is turned to start so I think I have eliminated that the yellow wire is bad from the relay board to the starter solenoid.

I can't tell from the schematic my manual if there are other things in the circuit I should check. I'm wondering if my ignition switch is bad.

Anyone have any ideas or insight? Any suggestions or directions would be gratefully appreciated.

Thanks,
Jsaum

[jsaum]

So here's where I'm at on the trouble shooting. The battery is good 12 plus volts and 550 cranking amps. Checked and rechecked all of the grounding points. I also used my set of jumper cables as extra grounds from the negative post on the battery directly to the starter housing and to the engine. I ran a separate wire from pin #6 on the relay board to the starter solenoid the starter still won't crank the engine over. A jumper wire from the positive cable to the terminal connector on the solenoid will crank the starter over like it should if using the key. I don't think I have a grounding problem and I believe that I have proven that the yellow wire from the relay board to the solenoid is good. I'm still getting 12 volts with the yellow wire disconnected from the solenoid and 9.5 with it connected. The first picture is the jumper wire I placed on pin #6 on the relay board. The second picture I have attached a lead to the volt meter so I can read the voltage when I try the key in the start position. The next one shows how the voltage goes down to 9.5 volts when the key is turned. The next two pictures show how with no wire connected to the solenoid I have 12.7 volts at pin #6 on the relay board ! I think my problem must be the starter switch.