Let me describe the total situation in detail.

Can not crank with key.
This is what we have and have done:
12.8 volts at battery
Only 10.3 volts at starter wire from switch in start position
Starter will work with a lead straight from battery to the spade on starter

12.8 volts at the ignition switch
10.3 volts at coil with ignition in accessory position.
No voltage drop from battery to frame.

Any ideas?

Thanks in advance

 

My first stab would be to clean all the main power wires, positive and negative. How are the engine to frame ground connections? Main positive to battery connections?

 

No voltage drop on frame or at switch input.
But when in accessory position there is a voltage drop on the switch output

 

Cannot trace the voltage drop. Do you think that it may be the switch itself?

 

Your starter main power doesn’t go through the switch so my bet would be no. I would disassemble all the main power connections, positive and negative, and clean and reassemble them first.
I’m not a professional car mechanic, I’m just telling you what I’d do.

 

Power to the starter is fine. As as I stated in the opening post the voltage drop is at the signal wire to the solenoid from the ignition switch.

If I apply 12 volts to the solenoid signal spade it starts. There is only 10…. Volts coming from the signal wire from the ignition.

 

I see. So you’re not getting enough power to engage the starter solenoid then? Then it could be the switch, or a poor connection somewhere else in that circuit.

 

will it start if you jump it? could be the battery is essentially dead or almost.

 

Fully charged. Starter works- just not engaging from ignition switch.

 

Just thought that I would bump this to see if any of the RRC gurus could be of any help. All of the details are in the opening post. Thank you in advance.