hey, im working on a 77 280. its auto,not sure if that will help here or not. while hooking the wires up to the alt and oil sender i found a wire that im not sure where it goes. our 75 manual car doesnt have this wire. does it go to the alt also or to the block? im trying to get all the grounds straightened out since it sat for about 8 years and my headlights and wipers arent working. thanks

ps, its the one standing straight up

It looks like a ground wire, probably for connection to the block (based on it's position and size). If you have a volt/ohm meter you could check for continuity to the negative cable terminal.

If it doesn't run to the negative cable, then turn the key to On and check for voltage.

Sam, I see three loose wires in the picture you posted. Two are black with ring lugs attached and the other is a light color with a bullet connector. Which wire are you concerned about?

Your photo shows two black wires that are not connected. The larger one (which you asked about) connects to the engine block, the other one connects to the alternator. Your photo also shows a small wire with a bullet connector, this one connects to a condensor that should be mounted on the back of the alternator.

yeah i was talking about the long black wire, i know the short goes to the alt. ill have to look into the one with the barrel connector, maybe thats my problem. i did have the long one attached to the block but i took it off because i wasnt sure if it went there or not. i guess ill have to mess with it some more. thanks for the replies, hopefully i can get it straightened out soon.

ok, i dont see where the barrel connector goes, our 75 doesnt have it connected either. for some dumb reason my computer wont let me download the fsm, it get to the last stage and says it cant download the file? must be my firewall settings. im going crazy