Not sure where to start on getting the gas gauge to work on my Far mall 340. I don't know if the gauge itself works since it wasn't wired up when I got the tractor. Also don't know if the gas sending unit works cause the wires to it are disconnected. The tractor was converted from 6 volt to 12 volt and I'm wondering if the past owner already let the smoke out of the gauge or just didn't hook it up cause he knew it was a 6 volt gauge. I have 6 volt running to the coil, so could I try out the gauge and sending unit by using this 6 volt supply? Not sure what to do about the positive to negative ground change over? Just reverse the wires on the gas gauge? Sparks and gas make for a big bang, so I don't want to do anything dangerous by mistake!
Pete

I am not sure it was equipped with a gauge, Look in the caseih.com website for parts, and if you find it under electrical, or accessories, or attachments, it does. The owners manual might have an answer, Do not hook up anything until you are certain it is wired correctly, and of the correct voltage. Jim

Pete 7; I also have a Farmall 340 w/non-operating gauges; fuel, temperature, amperage and incorrect tachometer. When the gas tank (13 gal. cap.) was near empty, I used a pen light to scope out the tank for crud/rust. The metal float isn"t any more, lying at the tank bottom. Warm weather for priming/painting will have me removing throttle - that"s a challenge with 50+ years of adhesion, but I did that last fall; pull steering wheel again and remove dash and sheet metal to remove sending unit which is between fill cap and top of dash. Your gauges don"t care if the battery is original six or converted to 12 volts. Check wire condition/connections/voltage - heed Jim"s advise. If you have large/good battery/ground cables, the six volt system will provide good starting in cold temperatures. This board"s late contributor Hugh MacKay had tractors starting well below zero. Fuel gauge location is top right. My Operator"s Manual lists "Fuel gauge filler cap" as an accessory. 371 057 R92 sending unit w/five screws 372 627 R91. I"ve been trying for several minutes now, but can"t get connected to the CNH website to see if it is still available, but that is a months old issue I guess. As w/so many parts for these tractors, my gut feeling is you won"t get a new one. I suggest running all new wiring for everything once the dash is off. I hope someone may provide a source for a new metal float. Post back w/your findings/results so others may learn if they use the archives - that is why I added to the subject line - for archive searching. Good luck w/your project.