Trying to install a new speedo cluster in my 84 CJ-7 stock. Everything works except the temp gauge. Sending unit is good. There were two wires, one black and one white attached to a bolt that holds the cluster in. I thought they were both grounds. The guy at Krage Motorsports told me that there are no wires were attached to the cluster when it was built.But that's where they were. I put this back together in reverse of the way I took the old one out. Any ideas what these two wires are for? I am sure they are part of the original harness. Also the temp needle doesn't budge when I ground out the sending unit wire. I am convinced that the gauge is faulty.