Jagsfan811 - You will need to remove the instrument cluster. The CVR is mounted on the back side of the gauges. The CVR has nothing to do with the speedometer. The speedometer is a mechanical indicator. It is run by a cable that attaches to the tailshaft of your transmission. The CVR also has nothing to do with your ammeter if your car has an ammeter. The CVR only powers the fuel gauge, temp gauge, and oil pressure gauge. The brake light has nothing to do with the gauges but it sounds like you have many electrical problems. You need to invest in a schematic diagram for your year Mustang. If you can't troubleshoot electrical systems then you need to find a person who can. You will need a VOM (volt ohm meter) and know how to use it.