GMC is a positive ground system, unlike Chevy. You may have damaged your regulator by hooking it up the way you did. The posti. cable goes to your frame. The neg cable to the starter. That small wire goes to the neg side of the coil. The positive side of the coil goes to the distributor. The gen on your regulator goes to the arm on your generator. The fld on the regulator goes to the fld on the generator. The neg wire from your voltmeter goes to the bat on your regulator. You should get a ign switch and a GMC Maintenance Manual. Save you a lot of headaches. Cecil.........
