R3T Fuel level indicator not reading.

[DodahMan]

As I was changing all the fluids on my 2015 R3T getting it ready to ride, I noticed that the fuel gauge was reading zero even though the tank is full. If anyone else has had this problem or has any suggestions, I'd like to hear from them.

There was no problem with the bike when put away last fall. The last time I rode it before putting it up for the winter, everything was working fine. It starts and runs fine although I haven't taken it out on the road yet because I'm changing all the fluids. All lights work (headlight, aux lights, tail light, brake light, turn signals). There's no error codes. Dummy lights on console all light up normally.

Now, here's what I did last week which would make me think that it has something to do with the problem but I was extremely careful and neat in my work that I describe in another post linked here:

New horns - relay necessary or not.

I replaced the silly OEM horn with two P1AA slim-line horns. They work perfectly and they are LOUD! As a precaution, I did install a harness with a relay so the horns are on their own circuit even though these particular horns don't require a separate circuit. For those who aren't familiar with the setup, the original horn wire goes to a relay which closes contacts and directs current directly from the battery to the horns on it's own circuit. It has an inline fuse. I don't think this has anything to do with the problem but it's the only thing I did so I thought I'd mention it. Again, the horns work perfectly.

I cleaned all the pins and sockets on the connector to the instrument panel with electronic contact cleaner. I thought that might be a problem because I did have the instrument panel off and the tank raised when I routed the horn wire to the battery.

There's no blown fuses. Just before I came in for the night, I checked the voltage at the fuel level sensor (on the right underside of the fuel tank) and it only read a few millivolts.

I do have the factory service manual but I hate circuit diagrams and they give me a headache trying to follow them with a magnifying glass. :-(

I'm going to finish changing the fluids tomorrow and then I'll work on the fuel gauge problem but, as of now, I'm stumped and not sure what to even at this point.

These bikes have bizarre electrical wiring issues. I thought I was stalled today with a no start.
Seem that the little switch on the clutch is pretty darn important. Mine is loose and sometimes the fuel indication works, sometimes it does not. Today after arriving at a hole in the wall diner in the middle of "podunkville", the bieatche would not start. Check engine light on. I fiddled with the ignition, switching key on and off. I was about to take the seat off to disconnect the battery for a ECU reset but fiddled with that ****ned clutch switch a bit and it started up!

If I am going to keep this motorcycle, this problem will have to be solved. Seems that the fuel flow and fuel remaining logic flows through that elcheapo clutch switch AS WELL as some kind of engine start logic. I am scared to take this thing out. No documentation in the manual about this switch or how it works.

 

[K&N]

It's the RC network driving the averaging circuit. Gas sloshes alot and the float moves up and down with the movement... the needle on the gauge is steady though. this circuit provides an averaging function thru a resistive/capacitive network that takes several cycles to charge once discharged. this can happen after ecu tunes as well.. Cheers.

 

[DodahMan]

It's the RC network driving the averaging circuit. Gas sloshes alot and the float moves up and down with the movement... the needle on the gauge is steady though. this circuit provides an averaging function thru a resistive/capacitive network that takes several cycles to charge once discharged. this can happen after ecu tunes as well.. Cheers.

What is a RC network? Oddly enough, the gauge was accurate for the first three or four tanks I ran. Would this switch have anything to do with the no start and CEL?

 

[K&N]

RC is a resistive / capacitive circuit; With each cycle of the alternating current, the capacitor charges thru the resister and, through this action, the circuit provides an average reading for the gas gauge. Again,this keeps the gauge needle from fluctuating as the float bobs around in the gas tank. Nothing to do with other circuits /starting etc. Cheers

 

[DodahMan]

RC is a resistive / capacitive circuit; With each cycle of the alternating current, the capacitor charges thru the resister and, through this action, the circuit provides an average reading for the gas gauge. Again,this keeps the gauge needle from fluctuating as the float bobs around in the gas tank. Nothing to do with other circuits /starting etc. Cheers

Thanks.

 

[Chip]

I've noticed my 08 R3T showing 0 gas on the gauge. I've also had issues with the start function. My question is could / would these issues be caused by a weak battery?

 

[DodahMan]

I've noticed my 08 R3T showing 0 gas on the gauge. I've also had issues with the start function. My question is could / would these issues be caused by a weak battery?

I bought a battery topper and have been keeping it topped up.
The manual is very weak on describing how this switch works and depicting the function. It's cheaply made with a plastic stem inside and a thin metal ring (for the electrical connection I guess). I can't figure out what holds it on. Some have cut the wires and s

I've noticed my 08 R3T showing 0 gas on the gauge. I've also had issues with the start function. My question is could / would these issues be caused by a weak battery?

I bought a battery topper and have been keeping it topped up.
The manual is very weak on describing how this switch works and depicting the function. It's cheaply made with a plastic stem inside and a thin metal ring (for the electrical connection I guess). I can't figure out what holds it on. Some have cut the wires and soldiered them together (making an electrical circuit complete?). I have not tried that. I have contacted Triumph about it, no results yet.

 

[Chip]

Thanks for the response. I've kept the bike on a battery tender. I try to plug in when the cycle is parked. I noticed when the voltage is in the 12.4 dc volts, the fuel gauge takes time to respond. I accounted for the increase from the alt. to making the gauge respond. The ignition is the same. Increase the voltage, and the starter responds.

 

[DodahMan]

Thanks for the response. I've kept the bike on a battery tender. I try to plug in when the cycle is parked. I noticed when the voltage is in the 12.4 dc volts, the fuel gauge takes time to respond. I accounted for the increase from the alt. to making the gauge respond. The ignition is the same. Increase the voltage, and the starter responds.

Perhaps these bikes just need a more powerful battery?

 

[K&N]

These bikes have bizarre electrical wiring issues. I thought I was stalled today with a no start.
Seem that the little switch on the clutch is pretty darn important. Mine is loose and sometimes the fuel indication works, sometimes it does not. Today after arriving at a hole in the wall diner in the middle of "podunkville", the bieatche would not start. Check engine light on. I fiddled with the ignition, switching key on and off. I was about to take the seat off to disconnect the battery for a ECU reset but fiddled with that ****ned clutch switch a bit and it started up!

If I am going to keep this motorcycle, this problem will have to be solved. Seems that the fuel flow and fuel remaining logic flows through that elcheapo clutch switch AS WELL as some kind of engine start logic. I am scared to take this thing out. No documentation in the manual about this switch or how it works.

Nice heads up, thanks