Go into the engine compartment, with the key in the 'run' position and ground (temporarily) the wire to the sending unit on the back side of the left head. The gauge should go to full hot. As soon as it does, pull it off the ground to not damage the gauge itself. If nothing happens, check to make sure you have power to the gauge itself. If you do, I would suspect a bad gauge. If the gauge checks good, replace the sending unit that screws into the back of the head Sep 2003 ------------------------------ With the ignition switch ON, ground the wire that goes to the heat sending unit in the head, ...briefly. The gage should go right to "HOT". If it does, the dash unit is OK, and likewise the wiring. If there is no response, then it could be one of 3 possibilities: a) the wire from the sending unit to the gage is open somewhere b) there is no power to the "ign" stud on the back of the gage c) the gage itself is bad With a test light and a clip lead or two you can check for a & b. If neither of them apply, then it's probably a bad gage. Sep 2003 -------------- The 12 volt gauges operate on a scale from about 33 ohms to 240 ohms. 33 being 'full' or 'hot' and 240 being 'empty' or 'cold'. SENDER - TEMP - 12V - NAPA - (1545220) TS 6460 - fits 57 - 64 w/ 43-51 ohms resistance @ 220 degrees SENDER - TEMP - 12V - NAPA - TS 6462 - fits 60 - 64 w/ 51-61 ohms resistance @ 220 degrees. --------------- Bob Glasscock If you changed the factory wire, you may have changed the resistance in the wire between the sending unit and the gage. I do NOT know what the factory wire is. For example, if it was single strand 16 ga. wire, and you put in single strand 18 ga., the resistance would be lower and the gage would see ground inappropriately. Same if you changed single strand to multi-strand. If the ohms between the sending unit and the input of the gage are lower than factory specs, the winding on the gage needle will react as if ground potential were reached sooner than in actuality. ---------- 6volt On 6.5V power (to the gauge) the needle position vs sender R is: C 130 ohm (or open) C 129 ohm Center 51 ohm H 21 ohm pegged Gnd