fuel gauge on 641

tractorguy2

Well-known Member
Trying to replace the fuel gauge on a gas 641. I bought a gauge and sending unit from Dennis Carpender. There are no instructions with the gauge. The gauge has three terminals. One marked "B" one "T" and the third "6 volt". I have a six volt postive ground system. I have the "T" terminal connected to the sender. The "B" connected to the key switch. I called dennis and was told to ground the terminal marked "six volts" so I did.

The gauge needle does not move unless I unplug the wire to the sender unit. Then the needle will move off of Empty and stop at 3/4 mark.

I have hooked the sending unit to my Ohm meter and the unit works when I move the float up and down.

I'm I wrong thinking the gauge has a problem?

I have put fuel gauges in two 12 volt conversions a 62 4000 and another 641. They both worked fine.
 
"I have hooked the sending unit to my Ohm meter and the unit works when I move the float up and down. "
..........and the Ohmmeter was connected to which two terminals?
 
(quoted from post at 14:59:40 06/08/16) "I have hooked the sending unit to my Ohm meter and the unit works when I move the float up and down. "
..........and the Ohmmeter was connected to which two terminals?
ever mind, I now see you were connecting to single terminal of sender.
 
Since I "believe" low or zero Ohms = empty and max Ohms=full, I would verify that wire from sender to "T" of gauge is not shorted to chassis along its path.
 
Little update.

I called the Dennis Carpender service line. First they told me I didn't have the gauge grounded correctly. I told them I have the gauge grounded to one of the screws in the regulator base.

Then they told me I should ground the gauge to the fuel tank. I tried that and it still didn't work.

I called them back. Next they told me my new fuel tank was not grounded. I needed to add a ground to the fuel tank. SO I used a wire with two clips and grounded the fuel tank the the battery ground strap. Gauge still didn't work.

I called them back.Told them adding the ground to the tank did not help. They said they would send out a new gauge!

What a day!
 

We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.

Back
Top