I have an 85K100RT that I have been working on thanks to all the info on this forum.

There was an earlier post where Crazy Fox posted the circuit diagram and the electronic workings of the 7L and 4L fuel level lights. My lights don't work and I almost ran out of gas (the bike is new to me). Is there a way to diagnose whether the circuit board is bad or the thermistor in the tank is faulty? What should the resistance be across the sensor in the tank? Can I power up the circuit off the bike to diagnose if the circuit is operating correctly.

Thanks for all your help!
This is a great Forum.

Hey RMT, we're nearly neighbors. Similar prob on my 85 RS. It was the bulbs on mine. If you pull the dash apart and swap a couple of bulbs around when the gas is low you may get some joy. Then you'll know for sure, and can replace the bulbs.

BTW, Shails Motorcycles in Vancouver has a great selection of new aftermarket, and used parts for these bikes. They have a website, a toll free number and will ship.

Thanks for the info on Shails. I am new to the province so I don't know all the best places to buy stuff yet.

Checking the bulbs was the first thing I did so now I wanted to take it further.