With the key in the ON position, take the wire off of the sender and ground it to the engine (any unpainted bolt, etc) The gauge goes to full COLD when grounded and full HOT when open (no ground). If this happens, replace the sender. If the gauge doesn't move, check that the wire is good all the way to the gauge, if so, replace the gauge. Also note that the gauge itself requires 12 Volts and ground. Normally three wires, the green one is sensor, black ground and orange is 12vdc. (Most are this way) Most failures are the senders. If you have an Ohm meter you can test the sender by measuring the resistance to ground while cold and hot. It should change and be fairly linear.
[This message has been edited by d1_bradley (edited 07-22-99).]
[This message has been edited by d1_bradley (edited 07-22-99).]
