70 Duster Starter Relay Voltages

With the new battery at 12.0v with the key in the START position, the starter is not drawing current in the car. If the engine was stuck and the starter just pulling current like crazy, the battery voltage would drop to 10 volts or so with all the current draw; it will draw much more than 85A if jammed.

Look at the battery - cable to the engine block and make sure that is very clean where it connects to the block. And then check the engine to trannie for a good ground connection and where the starter bolts into the bell housing for a good ground. I would even go to the extent of putting the old starter back in, and using one side of a jumper cable to connect directly from the battery - to the starter case and see if that helps.

BTW, taking out the starter may have unjammed something (the solenoid) or made some corrosion go away (causing a bad ground). And, the solenoid may have been jammed and not moving as noted above; it has to move to make the battery connection to the main starter windings.

By any chance do you have a separate big cable from battery + to the starter and another smaller wire to the starter relay's big lug? If so, the battery + cable to the starter may be bad.