I have a 1983 VF1100C I purchased in April 2009. I've run out of fuel twice for two reasons, one is the dial on the to reset it to zero was missing and the sensor was not turning on the low fuel light. I purchased the knob for the to reset it but also purchased a replacement sensor for the auxiliary tank.
Before I tinkered I checked the new unit for resistance between the two leads. My meter shows 1 when there is no connectivity and all zeros when you short the two connectors on the meter. When I put the meter on the two leads on the new unit I had a resistance of .673. The old sensor showed a constant 1 on continuity so it is obviously dead.
I drained the fuel from both tanks. There is a tube connecting to the rear bottom of the aux tank in front of the rear wheel. Fuel will shoot out when you disconnect so have a can and similar size tube to connect for draining the fuel remaining in the bike. Make sure you have the gas cap open so you don't end up thinking it's empty because the seal prevents air from getting in to evaucate all the fuel. Once the tanks are empty disconnect both leads to the sensor, remove it from the aux tank and install a new one. The one I took out was larger and had 6 holes for sensing the presence of gas whereas the new unit is 33% smaller than the old and only has three tiny holes in the bottom of the sensor. I tried cleaning the old one with a cloth then blew it out with an air compressor. I tested continuity before and after and both showed it dead. After installing the new unit I added the 1.5 gallons I'd drained back into the bike. I drove to the local station to fill it and while driving the low fuel light would come on then go off depending on whether I was accelerating or slowing down. Once I filled the tank (2.57 gallons on top of what I had) the low fuel light stayed off. Looks like the sensor just needed to be replaced.
I bought the replacement sensor at Power Motor Sports, it lists for $72.69 but they discounted it to 57.59 plus shipping.
Before I tinkered I checked the new unit for resistance between the two leads. My meter shows 1 when there is no connectivity and all zeros when you short the two connectors on the meter. When I put the meter on the two leads on the new unit I had a resistance of .673. The old sensor showed a constant 1 on continuity so it is obviously dead.
I drained the fuel from both tanks. There is a tube connecting to the rear bottom of the aux tank in front of the rear wheel. Fuel will shoot out when you disconnect so have a can and similar size tube to connect for draining the fuel remaining in the bike. Make sure you have the gas cap open so you don't end up thinking it's empty because the seal prevents air from getting in to evaucate all the fuel. Once the tanks are empty disconnect both leads to the sensor, remove it from the aux tank and install a new one. The one I took out was larger and had 6 holes for sensing the presence of gas whereas the new unit is 33% smaller than the old and only has three tiny holes in the bottom of the sensor. I tried cleaning the old one with a cloth then blew it out with an air compressor. I tested continuity before and after and both showed it dead. After installing the new unit I added the 1.5 gallons I'd drained back into the bike. I drove to the local station to fill it and while driving the low fuel light would come on then go off depending on whether I was accelerating or slowing down. Once I filled the tank (2.57 gallons on top of what I had) the low fuel light stayed off. Looks like the sensor just needed to be replaced.
I bought the replacement sensor at Power Motor Sports, it lists for $72.69 but they discounted it to 57.59 plus shipping.
