quote:I just replaced the solenoid
Since the starter "works", the solenoid didn't need to be replaced.
quote:it has a direct power line from battery via a 30 amp relay that is triggered, or should be by the ignition switch?
Yes, the relay should be activated by the ignition switch.
quote:1. Ignition switch? (can it wear out in some fashion or get gummed up enough that it would not work specifically for the coil.
Yes. There is one contact for the ignition and another for the start. When the key is turned to the start position, both the ignition contact and the start contact are joined (electrically) by a movable contact. The ignition switch can be removed from the car, carefully disassembled, and (in most cases) cleaned. I think that Larry Finch still has some NOS ignition switches for sale.
quote:2. Control box? 3. the rear loom?
Possible.
quote:I also assume that if the starter is running that, I have a good earth. The braided lead coming off the back of the ZF to the body looks ok?
Yes.
As I posted above, add a temporary jumper wire from the battery side of the starter solenoid to the input terminal of your ignition relay. If your ignition relay is a Bosch type, terminals 85 & 86 are the coil circuit. One of these two terminals goes to ground and the other is from a switched +12 volts source (ignition switch). Terminals 85 & 86 can be reversed, meaning you can ground either one and the remaining terminal receives the switched +12 volt wire. On the '71 cars, the wire from the ignition switch is the red wire coming out of a molex connector by the ballast resistor. You can also connect the jumper directly to the +12 volt lead that goes directly to your ignition (instead of connecting it to the relay).
If the car starts with this temporary jumper, you won't be able to shut down the ignition (turn the car off) with the key. You will either need to stall the car with the clutch (trans in gear, heavy foot on the brakes), or get out of the car while the engine is running and remove the jumper.
If you would like to PM me with your phone number, I will give you a call.
John