M5jag

My first problem is that I have purchased an MGB based kit car and several of the dials and switches appear to be salvaged from other vehicles. The one giving me problems at the moment is C A V unit on checking the Internet all advise comes back to historic WW11 vehicle. The part is a 47A-29. It appears to have no use on the car but there are a couple of wires attached behind the dash but I cannot follow where they go. Any advise would be a help. m5jag