During the winter I took some gift cards I had received and bought the HD 75338-09 fuel gauge for my Sportster. It is fairly expensive at $250. I know everyone just says use the trip odometer. I just decided I wanted something more visual.
I finally got around to installing the gauge this weekend. It went well enough until I had to make some connections with existing wiring. The service manual was very helpful with pictures and directions. Taking off the fuel tank and removing the fuel pump where fairly start forward. Removing the fuel pump fuse and main fuse were again well documented. When it came to the wiring Things were not so clear. There are loads of schematics in the back, but they don’t show the actual harnesses, connections and locations. The directions for the fuel gauge used such useful directions like “Find fuel sender resistor assembly [200A] located between the oil tank and frame near the seat pan.” Another was “Splice the orange wire of the fuel gauge into the orange/white wire… near rear lighting connector [7A] located in the seat pan area.” Not having seen these types of things it would have been nice to see a picture to know what I was looking for.
I finally found the fuel sender resistor connector on the opposite side that the directions lead me to believe. I guess you could saw it was on the driver’s side not the passenger side like I thought. Below are some pictures showing the hiding place, the sender resistor connector and the resistor for the low fuel indicator light.
The last piece to find was the 7A connector. There was just nothing I could see for the 7A. That which I could see was labeled so I knew they were not the elusive 7A. I finally got the idea to pull and move the ones I could see and this revealed the 7A underneath the others. Again I have a picture showing the lighting connector.
The earlier stages I didn’t take pictures since they are well documented in the instructions. It was interesting to see what it is that turns on the low fuel light. It is just a small plunger like piece that once it isn’t floated by fuel, sends the signal and the light goes on. That was removed and replaced with a long sensor, that I am assuming detects the fuel level and lights or turns off a light as fuel is used. Finally, once it is low enough where it isn’t detected, the fuel gauge starts the final line to blink.
It was an interesting experience to install the gauge and best of all it works. The final couple of pictures show what the gauge looks when near empty and then full.
UPDATE: I just got to the end of the first tank with the gauge. The small indicator for when fuel level is low starts to blink when the tank had .8 gallons left. I noticed it blinking and went a few more miles to a gas station. I filled it as full as possible and it took 3.7 gallons.
Low fuel light resistor