Does anyone know what range the fuel tank sender operates at? My background is with GM cars, and they used 0-90 ohm senders for years. I know my tank is full, my old gauge is bad so I need to buy a new gauge first. I'd Ike to pick up a generic non bobcat gauge to save some coin, just need to know what ohms they operate at.
Bumping this back up. nobody has any idea what the range? I found one reference online that says its 240-30 ohm. I can't really reach my sender with it in the tank to test it. going to have to pull it out to check I guess.
Why don't you just test the ohms coming from the sender at the gauge? Remove connector at gauge and test it there then you don't need to get near the sender. That is assuming the sender is ok.
Last one I played with was a VDO sender and it was 0 - 90 Ohms.
I might try that but I have to replace my exhaust so I'm right there above the tank anyway. Since I have the hydraulic tank off to fix the exhaust I want to fix the fuel gauge too.
what model machine? :drinkup
Take a potentiometer and connect it from the low side of the circuit to the high side and connect that to your guage and measure the voltage that the guage needs to read full scale then measure the resistance that the pot was set at to make that happen.Start your measureing with the pot set at a very high resistance so you don't damage the guage by applying too high a voltage.Ron G
If you read my original post I don't have a good gauge. My machine is a model 853.
So you want a new gauge to match your existing sender, why can't you measure the ohms of your current sender?
I can but I don't know if the sender is any good either. Which is why I was hoping someone knew what range the sender should operate in
My understanding of fuel senders.......there are 2 common types. The GM system that is 0 to 90 ohms - if you pull the wire off the sender the gauge will read full and drop to empty when you ground the wire. Everything else uses the 240 to 30 ohm system. When you pull the wire off the sender, the gauge drops to empty and when you ground the sender wire, the gauge reads full scale. If you can get to your sender wire (I know 853 fuel tanks are under the engine) you can trouble shoot and see which system bobcat uses. I'm not sure but I'd guess it's the 240/30 ohm system.
Sorry,my error.Buy a matched pair,sender and guage.Ron G
Ok tried to troubleshoot a little bit tonight. First tried checking resistance at the sender wire at back of gauge- got no reading. Second I lifted the cab and poked around with the sender. No matter what I did or tried I could not getting any ohm reading. So I think my sender may be bad. I'm going to bite the bullet and just order one to start emilinating possibilities. I did find in my spare parts stash I have what should be a working 240-30 ohm gauge so if I get a good sender I can test it against this. Does anyone know what size the sending unit nut is? It's large, and my 3/4 drive sockets are all 12pt. I got an 1 11/16 socket on it, but it was slipping off.
Just wanted to follow up the bobcat fuel sender is in fact 240-30
it's an oddball size, dont remember what it is. bobcat sells a socket for the (block mounted) aux couplers that is the same size. :drinkup
I ended up not even having to change the sender. my gauge was bad, and my new first new gauge I ordered was also bad! once I finally got a good gauge it works.
Thanks for the follow up Joe.Ron G