# Bobcat 763 F series fuel sending unit problem



## Dale Paul (Feb 23, 2014)

I recently bought a 2002 Bobcat 763 Series "F" that had a faulty battery meter and fuel gauge. I corrected the battery meter. I've checked the fuel gauge wiring and get "0" ohm readings and have settled on the fact the fuel level sending unit in the fuel tank is bad. Is this a hard part to replace? can I access the fuel level sending unit with out removing the fuel tank? Other wise the skid steer is in great working condition. Any assistance is greatly appreciated. Thanx.


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## VA-Sawyer (Feb 23, 2014)

0 ohms from where to where? Can the meter register down to a few ohms? I don't have the manual handy to verify the values, but it seems like it gets down to less than 10 ohms at one end of the travel.
I have a 753F and can just access the top of the tank via under the cab. You have to pull the engine and pump assembly to really get to the tank. Not hard if you make the jig they show in the manual, but pretty messy due to hydraulic fluid.
Where are you located? Oh yea, welcome to AS.


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## Dale Paul (Feb 24, 2014)

VA-Sawyer said:


> 0 ohms from where to where? Can the meter register down to a few ohms? I don't have the manual handy to verify the values, but it seems like it gets down to less than 10 ohms at one end of the travel.
> I have a 753F and can just access the top of the tank via under the cab. You have to pull the engine and pump assembly to really get to the tank. Not hard if you make the jig they show in the manual, but pretty messy due to hydraulic fluid.
> Where are you located? Oh yea, welcome to AS.


Thanks for your reply VA-Sawyer. I live in Penn Yenn NY. I've worked in electronics since high school, job and hobby, so I have a very versatile high impedance multimeter that can read 10ths of ohms. I removed the black and purple wires from the gauge, take a 9V battery and get a nearly full meter deflection of the fuel gauge. I trace the purple wire from the gauge to the first large round connector and take a reading from both ends and get good continuity. I take a reading from the other side of the connector to circuit ground and get "0" ohm reading, I believe the sending unit resistance should be between 33 and 246 ohms. I don't cherish the thought of pulling the engine, this has been the coldest winter in several years here in upstate NY and I have no heated building to work on it. I may resort to filing the fuel tank, noting the hours and monitoring the hours and using an electrician snake to probe the fuel level and when the level gets down to a predetermined point, making a note of the hours again and go from there. I appreciate the information and I'll let you know what I find. Thank You. Dale Paul.


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## VA-Sawyer (Feb 24, 2014)

I don't think the snake will help much, I believe you will have an inlet screen where the filler hose connects to the fuel tank. I did take a minute and look in the service manual for fuel sender resistance specs, but didn't find them. A quick check of the wiring is to check for voltage at the top of the sender with the key on. 0 volts - problem in wiring. Full 12 volts - probably an open in the sender. 3 to 10 volts - means sender is getting voltage and is probably OK. You should be able to get a probe on the sender without too much trouble. Just raise the cab and crawl back there. It really helps if you keep it clean.


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## VA-Sawyer (Feb 24, 2014)

You should have full battery voltage on one side of the fuel gauge with the key on, and the same voltage on the other side as you have at the top of the sender.


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## kr5258 (Feb 24, 2014)

You can pull the sending unit out of the top of the tank. Disassemble the top connector portion of the sending unit and clean everything up with a scotch brite or similar abrasive pad. Condensation causes corrosion in this area and skews the resistance. This corrected the fuel gauge error on my Bobcat.


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