Re: Gauges
Each gauge requires +12 volts when the key is on. They also require a ground connection. Temp gauges have a connection to the temp sender on the engine. Same for the fuel sender. If you have a multitester that tests AC, DC and resistance (ohms) it makes troubleshooting much simpler. Since you have two gauges inoperative, I doubt its the senders. I would check to make sure +12V and ground are present on the two non-functioning gauges. Although temp senders do go bad, it is relatively rare. Fuel senders on the other hand are literally trash when they are brand new so they do have a higher failure rate. Fuel senders can be checked with an ohm meter. If you have a rough idea how much fuel is in the tank, disconnect either the ground wire or the sender wire at the sender. Measure the resistance (sender terminal to ground). If the tank is empty or near empty it will read 200 - 240 ohms. If it's half full it will read about 103 ohms and if the tank is full it should read about 33 ohms. If you get no reading at all or if the sender shows a dead short, it must be replaced.
