Another fuel guage issue

[crunchie]

Just bought a 2015 Viper R-TX DX and the fuel gauge is wonky. Removed the sending unit, tested the resistance, 0 when full and 100 empty, seems that's close to normal. When I start the engine with sending unit in my hand and move the float from empty to full, or even at about half, the dash gauge doesn't move, stays at about 1/3 full.
So the sending unit seems it's doing it's thing but the fuel bar on the dash doesn't move?
As one poster suggested to check the fuses, I'll do that today.
TIA

 

[RobX-1]

I'm fighting a fuel sending unit issue with my 08 Apex but my gauge just displays the fuel bars as full and flashes the bars as if the connector to the fuel sending unit is not connected. I too removed mine and ended up determining there is a bad spot on the board near the empty position of the float; position it to full, and the fuel bars stop flashing and slowly creeps up to full. Keep in mind that the fuel bars displayed on the gauge do not "immediately" reflect position of the float so while moving the float, you need to stop and wait for the fuel bars on the gauge to catch-up, per-se. Although I did use an emery cloth to clean up the contacts and such and was able to get the sending unit to work properly as I moved the float to the empty position, once it got near to that position, it would start flashing the fuel bars. I even used an ohm meter to confirm and have a new unit on order. Unfortunately, for my particular sending unit, it is on backorder from Yamaha with no ETA (ie. it has to ship from Japan and who knows when it will arrive in the states) so ended up purchasing a used one off eBay to finish out the season.

 

[crunchie]

Isn't this called hijacking? Not trying to be rude but I thought someone had replied to my thread.

 

[RobX-1]

Hijacking a thread is to steer off topic. Providing information pertaining to the issue you created the original post for is not. Now, if you created similar posts in other forums and someone posted to it, then that is called double posting; not to be rude.

My post was not intended to seek help from others (as I already resolved my issue) but to offer YOU some things to try that I went thru when troubleshooting an issue with my fuel sender.

 

[crunchie]

OK

 

[crunchie]

Hijacking a thread is to steer off topic. Providing information pertaining to the issue you created the original post for is not. Now, if you created similar posts in other forums and someone posted to it, then that is called double posting; not to be rude.

My post was not intended to seek help from others (as I already resolved my issue) but to offer YOU some things to try that I went thru when troubleshooting an issue with my fuel sender.

Oh, it's because I had already wrote that I tested the sending unit and it was reading correctly out of the fuel tank ohm wise but the display is not reacting to the actual level. Going to check the fuse box today, don't know what else to do other than bringing in to the shop and we're in mid season so that's not going to happen.

 

[RobX-1]

Again, my post was not to hijack your thread by steering it off topic or posting my own issue within your post rather than create my own. When you create a post concerning an issue you are troubleshooting, unless I'm mistaken, the intent is to get others' input as to what could be causing the issue. In doing so, you will get replies that range from "here try this" or "hey, I had a similar issue and here's what I've done". My post would fall into the latter category. When that occurs, yes, there may be times where the information provided includes steps you may have already done but there's still a chance something can be gleamed from those responses.

Case in point, I realize you already tested with a meter the fuel sending unit but as I mention, did you remove the clip holding the arm you are moving on the sending unit to the FULL or EMPTY position to expose the circuit board it travels along and clean with a piece of emery cloth? When I used the meter to record the readings, I didn't just do it at the FULL and EMPTY positions; I also measured as I moved the arm along its path from the empty to the full position. That is how I found there were bad spots on that board. When I removed the clip holding the arm and cleaned that section of the circuit board with a piece of emery cloth, I was able to get accurate readings in places I was not able to before (ie. from the 1/4 tank position to 1/2 tank position) but ultimately, there ended up being a short at the EMPTY position and hence why I had to order a new one.

 

[crunchie]

Honestly, I did not monitor the whole spectrum very closely. But that’s a very good point, going to try that today. So the arm that runs across the metal doodad can be removed to gain access to the doodad?

 

[RobX-1]

Yes, on the back side of the fuel sending unit is a clip with a washer below it. I just used a small flat head screw driver to get up underneath the washer and gently pry up to lift clip off its peg to allow the arm to be removed:

Once removed, you will see the track where the arm moves along that can be cleaned with an emery cloth. Also, there are contacts on the arm itself that can be cleaned up. When cleaning those contacts, if you apply to much pressure, you may have to reposition them to their upright position. You just want to ensure they are not flat as once assembled, those "brushes" (for lack of a better term) will not make contact with the circuit board:

 

[crunchie]

Had a similar issue with my wife’s 1999 Venture, but it was fubar, Ended up installing a new one. Tks

 

[crunchie]

Yes, on the back side of the fuel sending unit is a clip with a washer below it. I just used a small flat head screw driver to get up underneath the washer and gently pry up to lift clip off its peg to allow the arm to be removed:

View attachment 171098

View attachment 171099

Once removed, you will see the track where the arm moves along that can be cleaned with an emery cloth. Also, there are contacts on the arm itself that can be cleaned up. When cleaning those contacts, if you apply to much pressure, you may have to reposition them to their upright position. You just want to ensure they are not flat as once assembled, those "brushes" (for lack of a better term) will not make contact with the circuit board:

View attachment 171100
View attachment 171101

Did exactly what you suggested and now working, thanks so much. Prior to putting the sending unit back in the tank, I fired it up and put the computer in diagnosis mode. Moved the arm open and close, the ohms were following the position. Is it possible the gauge reads in increments of like maybe 5? Not sure if I'm clear on that question.

 

[crunchie]

In other words does the bar gradually move from right to left , or is it more like sections, as the level drops. Thank you Viper owners.