Does anyone know how to run a test on your gauges. IE, the fuel gauge and temp gauge on my 59 ranchero do not register anything. I just replaced the dash voltage regulator with a NOS one I found. The temp sending unit is new for sure (I installed it) and I was told the gas tank sending unit was also new. I have checked and I have steady power to the volt regulator and flashing power out to the gauges, but they do not register. WTF, over?
Go to the sending unit end of both gauge wires and disconnect them. Now hook a jumper on the wire and go to Ground. Now switch the Key on and watch the needles. If they both come up it's the sending units (don't leave the Key on). It's common for some people to use Teflon tape on temp senders, bad idea. It stops the sender from grounding. I've also found Gas Tanks not grounded well enough to make the sender work. I Make a jumper from sender mount screw to the Body to cure that problem. The Wizzard
Tape 3 1.5 volt batteries together to get 4.5 volts and attach with leads to the back of the gauge. Make sure to Disconnect the gauges from the wiring harness/circuit. 4 1/2 volts should make a Ford gas, oil or temp gauge rise to near the top. The CVR (constant voltage regulator) reduces the battery voltage to 4 1/2 volts to run the gauges. You should use a 12Volts CVR for use with 12Volt battery and 6Volt cvr only on a 6 volt system Good Luck
OK, did the test above (grounded the wires at the sending units with ignition on). The temp gauge was a no go, no change at all. The fuel gauge came up fast so it had to be either the sending unit or as stated, no ground at the tank. Did the following. 1) pulled the temp gauge. both wires inside smoked. Treid, but can't connect hair thin wires. Need another gauge. 2) pulled the fuel sending unit. Cleaned the mounting with sand paper to insure a good ground. Also drilled hole into the sending unit, screwed on a good tight ground wire and grounded it to the frame well. Gas gauge now works but shows only a 1/4 tank. Tank is full. What do you think? Need a new sending unit? This one is only two years old. Anyone got a temp gauge for a 59 Ford?
I don't have a spare, but you can get a gauge bucket from any Ford 1940-1979 or so and put your needle and face on it. Oh yeah, some are backwards - my '40 Ford Temp gauge reads 'H' (all the way right) when off. The others are all the way left when off.
Take your sending unit out and check the Float. It's probably 1/2 full of gas. If so it's to heavy to rise all the way up. Fairly common with old Br*** floats. If your real careful you can find the hole and shake the gas out then soft solder the hole shut. You'll get a few more years out of it. The Wizzard
I pulled the sending unit looks new and has a white plastic float. No gas in it either. Makes me go hmmm. I found a guy with a gas and temp gauge so I bought them, Should be here early next week. I also ordered a new sending unit for fuel and temp. This should fix it.......I hope. Thanks for all the help.
If you have an volt-ohm meter you may want to measure the sending unit for resistance (disconnect the wire from sender unit before measuring)from sending unit wire to ground of sending unit while in the tank. Take the measurement with the full tank of gas. It should be no more than 5 ohms or so. If over then the sender unit is bad. You can compare the new one for the same readings when in the tank.
Testing your float/sending unit is a lot easier before it's installed. wire the float into the system just as you would if it were mounted in the gas tank. Run the float thru it's movement and watch the needle on your fuel gauge. Look for dead spots as you move the float up and down. .
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