Engine won't turn over -- possible ground fault

[dduclaux]

To all -- I've completed a rebuild of my '79 3.0L SC engine. Put it back in the car and the starter won't turn the engine over. The starter gear is engaging the ring gear but won't turn the engine over.

So what have I done to troubleshoot:
(1) removed the spark plugs and turned the engine over by hand, no problem.
(2) pulled the starter, took it to a starter shop, they tested it under a load, starter checks out OK.
(3) trickle charged my new Optima battery, had it tested under a load at the same starter shop, battery checks out OK.
(4) checked my ground strap from the transmission to the chassis, clean and snug.
(5) cleaned my battery terminals and connectors, clean and tight.

I do have a question as to tracing the cable from my positive battery terminal to the red wire to my starter. Can anyone give me insight as to the path that cable follows and where it steps down from the heavy battery cable to the 10 gauge (or so) red wire that connects to the starter?

I am open to all suggestions. Thanks, Duane

[jstobo]

You should have two wires at the starter "big lug". The big thick battery cable and the 10 gauge that goes to the alternator. A yellow wire(from ignition switch) should also attach to the solenoid at a smaller connection. If you only have one wire at the big terminal on the solenoid then my guess is the battery cable is not connected. If the battery cable is connected-hook up a voltmeter at the starter(big lug) and have someone try to start the engine. The voltage at the starter should not drop below 9 volts. If it does you may have a cable problem. Good Luck.

[Nitrometano]

Make that test. If not turn over. Take the spark plugs appart and turn the engine by hand. Is the engine does not move you have a mechanical problem.