67 buick riviera

im lost here and hope someone will help. i have a 67 buick riviera in my shop and a tech disassembled the vehicle and then quit. im down to the starter and cant seam to get the wiring down on it. i have a new positive cable and neg cable on it. the reference wire lites up when the key is on and the signal wire lites up when you turn the ignition to the start position. but all wires on the starter it just turns real slow and makes a bunch of clicking noises like its not getting enough power. new batt to. and i have a new starter on it. so im lost at this point and cant find a repair manual for this vehicle to get the wiring digram for it. i feel like im missing something obvious. thanks for any insight on this

any v-8 buick that year should be wired the same way on the starter cuircut at least. is the neg. battery cable going to the body ooof the car or going to the body of the starter? is the timing set on the engaine or maybe a bad starter. far as wiring goes the “s” is the switch leg the “i” is the dist. power

What does a voltmeter across the battery terminals read? Should be 12.5

it is

nope 2 new starters and they both do the same thing. neg cable to the block of the the car and small wire off neg cable to the body of the car

Don’t know much about GM cars. Does a 67 Rivera starter need to be shimmed out like a Chevy? If it is in too tight is could bind up and crank slowly.

nope not grinding it clicks real fast in the solenoid and turns over slow like a voltage drop but i measured the voltage and its fine

If you bench test the starter does it work?

All good suggestions here but @BigMarc may be on to something here. Make sure the engine is grounded to the frame. In addition…make sure the negative cable is attached to the frame. Make sure the frame is not painted where the negative cable is attached.