There is no ground wire. The alternator is grounded just by it being mounted in place.
So where is the ground wire at?
The alternator is grounded by the outside casing mounted to the metal mounts when the alternator bolts are tighten up. It is grounded to the engine itself threw the mounting brackets.
Check the connections under the rear seat cushion, that is where most of the major connections are located, Caddies are kinda different with thier wiring setups, if you believe your having grounding issues you can always add more grounds, but I have found most issues under the seat.
My 2000 Deville has a wire coming from the alternator to the frame look down beside the fuse box under the hood my wire was broke my car wouldn't start I replaced the wire it started
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