fuel gauge

[Tic Wilson]

2005 Monterey
Fuel gauge reads full most of the time.  Occasionally it will show lower levels, but only when nearing empty.  I am using the alladin trip monitor to determine my fuel usage, so I don't run low.  I know the fuel sender must be on the tank, but I have no idea where or how to access it.  Does a short circuit cause a full reading?  Or an open?
I conjured up in my mind, that the float gets stuck in the full position and does not drop down to the fuel level until the tank is less than 1/2 full and we hit a road bump to set it free.  Appreciate any ideas on this.  Thanks!

[Gerald Farris]

Tic,
An open circuit to the fuel gauge gives you a full reading. You assumption about your fuel gauge float sticking is almost impossible. The tank unit detects fuel level with an electrical contact that is attached to the float, and it travels up and down a rheostat varying the resistance in the circuit from the dash gauge to ground. You problem is most likely a poor contact between the contact attached to the float and the rheostat.

Gerald   

[Tic Wilson]

Thanks Gerald!  Any idea where that sender unit is located?  Or how to find it under the coach?

[Gerald Farris]

Tic,
I am not sure where the sending unit is located on a 2005 Monterey. You can just look for the location where the wires go to the fuel tank.

Gerald

[Bob Stone]

Tic, check the thread started by Stan Simpson on I believe July 28, 2012.

I have the identical coach with exactly the same problem. No cause or solution yet. It seems to be a common problem with our year and model.
The above noted thread has a good photo of the tank level sender connections on the tank. This fitting can be seen by peering between the front of the slide out bin (when extended) and the front left tire.

The closest I could come to a solution was to determine which sending unit was installed in the tank and have another sent from the manufacturer which I believe is in Florida.

Good luck with yours and I'd really appreciate hearing if you find a solution.

[Bob Stone]

Tic, I've done a little more digging and found considerable information on the iRV2.com forum by doing a search on 'fuel gauge and Monaco'.  Also, there's a good chance that the fuel tank level sensor in our era of Beavers was manufactured by Centroid Products. A check of their website www.centroidproducts.com and/or a google search on Centroid will produce a lot of information on their products: calibrating, troubleshooting etcetera.


Bob

[Joel Ashley]

In searching Stan's posts as per Bob's suggestion, I noted a more recent resolution Stan found that bears some attention, Tic:

http://beaveramb.org/forum/index.php/topic,3513.msg26813.html#msg26813

I'm not sure Stan ever fully said what the original solution was, only that new wires were strung, and then restrung.  The first rewire implies to me that at least one of the wires was damaged in an inaccessible place, and that was the cause of his not getting a proper gauge reading.

The fact that it occassionally works hints at a partially damaged wire or poor ground in addition to a possible bad sensor.  Getting readings more often when fuel is low supports, to me, even more of Gerald's theory of bad sensor contacts.

Joel

[Keith Duner]

A little late to the party but I had this picture of the sending unit on my desktop so I thought I'd post it.  Our coach is a 2005 36ft Monterey.  As already stated, the sender can be seen behind the driver side tire (if cut hard to one side).  It may be covered over with road schmutz and hard to see, but it's there.  Our fuel gauge also has questionable accuracy.  I use math more than the gauge.  Seems like the sender takes a "casual" approach to reporting the fuel level to the gauge (kind of like traffic laws in Italy...).  More a suggestion than a report.
 

[Tic Wilson]

I am updating an old post, because first, I am the one who started it, and I wanted to provide an update.   And second, thanks to those who provided clues.  As noted, the fuel sender is on the top and driver's side of the tank.  Road gunk was mentioned, as possibly hiding the wiring, but I am thinking it is also fuel seepage.  In any case, while parked at Master Tech in Elkhart to have the windshield replaced, I purchased a can of GUNK engine degreaser and thoroughly washed the wiring at the sensor.
The gauge has worked ever since.  A combination of road materials and seeped fuel, either shorted or grounded the circuit.

My apology to Master Tech, but the ground there was already stained.
Tic Wilson
2005 Beaver Monterey