dman2123 said:
the grond from the battery was grounded in 2 places. one on a bracket to the frame and also one a bracket above starter. what is the purpose for this.
The proper ground points should be a direct connection from the battery to the frame rail below the battery tray and then from there to the clutch cable bracket on the transmission.
Electricity travels in a loop from a power source's (in this case the battery) positive post to it's negative post (well, it's actually the other way but positive to negative makes more sense). The car body is made of metal... Metal conducts electricity - meaning electricity can flow through it. Connecting the negative terminal of the battery to the car body, allows you to simply connect the negative wire of whatever device you're running to the body of the car instead of running an extra wire all the way back to the battery. This is known as "grounding" the device.
I think the term ground came into use because the neutral conductor in A/C house wiring typically leads to a heavy rod driven into the ground outside the house. The earth itself acts as the return conductor between a power station and home.
Anyway, you need the engine ground wires because the engine isn't bolted directly to the car. The weight of the engine is carried by rubber mounts which are then bolted to the car. Rubber is an insulator - it doesn't conduct electricity. Connecting the engine block to the body of the car with a ground wire lets you also ground devices to the engine block and not just the car body.
In the case of the starter, power flows from the positive battery post, down the battery cable to the starter solenoid. The solenoid is a sort of heavy duty relay (an electricly controlled switch) that's controlled by the ignition switch. The solenoid also moves the starter gear so it meshes with the teeth on the flywheel. So when you turn the ignition switch to start, the solenoid meshes the teeth of the starter with the flywheel and allows power to pass from the battery cable on to the starter motor. The power flowing through the starter motor causes the motor to spin, cranking the engine. The electricity then passes into the metal casing of the starter. The starter casing is bolted to the transmission, so power passes into the transmission casing (also metal). The transmission casing is connected to the negative battery post by the engine ground wire, so power passes up the wire and back to the battery, completing the loop.