Fuel light sensor issue

So I bought this 1985 xj700 barn find and the previous owners decided to do some custom wiring job and now I'm a little confused haha.

With the fuel light wiring, I traced the power wire along the harness (headlight to seat) midway down the gas tank power wire goes through a resistor and continues to the fuel petcock I believe. I'll add photos.
Can anyone tell me the size of the resistor that may be needed? Or what might need to be done.

 

Austin S,
Welcome to the forum and congrads on the xj700 find. Can you give us a little more background as to what you have done with the bike. Have you cleaned the carbs, checked the gas tank, looked at the oil, found the air box, see if you have spark.

What I am getting at is, how about making sure the bike will start, run and is worth all the hard work to come?

 

doides are #45 on drawing
#25 is oil light #38 starter solinoid

 

The picture you posted is a diode and not a resistor. The diagrams are a bit confusing on wire color, but that appears to be L/W to G, which would be the wiring for the oil indicator light that is used to illuminate the light when the starter button is depressed. If so (you need to verify where those wires go), then the diode would be in backwards as the cathode (striped end) normally connects to the L/W wire. Normally, this is done through the diode block but since you mentioned creative wiring by the PO perhaps they removed the diode block and installed a standalone diode?? It is also odd that L/W wire is a bullet connector as this is normally part of a multi-pin connector.

History on the bike and preliminary checks on condition as Timbox suggested would be a good start. It looks pretty abused from the pictures - making sure the motor is not locked up from sitting would be a good place to start.