I also have an 86. yep, it's a black box about 2" wide, and 5 or 6" long. it's up under the dash by the steering column I think, there is a bundle of wires with a connector that goes into one end. I think there might also be a aluminum heat sink on one side of it. If I remember they are very expensive from GM. I got 2 from a salvage yard and one of them ended up working /forums/images/icons/smile.gif Not a hard repair.