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Cabo 40 Convertible fuel gauge - CAT C12's

Discussion in 'Cabo Yacht' started by Capt Maritime, Mar 13, 2023.

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  1. Capt Maritime

    Capt Maritime Member

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    I have a 2005 Cabo 40 convertible with caterpillar C12's. The attached photo is of a Cabo 40 with MAN's showing the fuel gauge repeater on the bridge. On my bridge this is where the caterpillar sync controller is installed and there is no fuel gauge anywhere else on the bridge.

    So for a Cabo 40 convertible with Cat's, where is the fuel gauge repeater or does the data from the tank sender feed into the Cat displays?

    Attached Files:

  2. Capt Maritime

    Capt Maritime Member

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    Pulled the drawings out and the fuel gauge sender feeds the CAT box.

    Cabo 40 Convertible fuel gage harness.jpg
  3. Capt Maritime

    Capt Maritime Member

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    A comparison to the above 40 Cabo convertible with MAN's. This is the set up on my bridge with my 40 Cabo convertible with CAT C12's. No fuel gauge on the bridge.
    Cabo 40 convertible no fuel gauge with C12 CATs.jpg
  4. Capt Maritime

    Capt Maritime Member

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    The below is a Cabo 40 express with C12 CATs and yes with a fuel gauge on the lower right hand corner of the helm. So there is a Cabo 40 configuration with C12 CAT's that includes a fuel gauge repeater, however for some reason it only appears to be on the express model.

    Cabo 40 express with guel gauge C12 CATs.jpg
  5. Capt Maritime

    Capt Maritime Member

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    Update on my fuel level gauge on the bridge. With the assistance of Carter CAT here in Virginia we found the fuel gauge displayed on the STBD engine CAT display. The tank is approximately 70% full based on my fuel burn since the last time I topped off the tank. The only issue is the the capacity display is erratic cycling between 70% - 90% sitting at the dock. I'm going to trouble shoot the connections and the tank sending unit next.

    CAT display stbd with fuel.jpg
  6. Pascal

    Pascal Senior Member

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    None of the cat powered boats i ve run had fuel gauge data in the Cat display and I don’t even understand why you would want that anyway. An external gauge works just fine… if you really want to rely on a gauge.

    personally I don’t rely on fuel gauge. Never. Especially with electronic engines which give you the amount of fuel burned since reset and to date. I use a spreadsheet with formulas on my phone, just enter the fuel totalizers, GPS miles, gen hours and the SS calculates what a left in the tanks, how much was burned, along with nmpg. It s far more accurate than any gauge I’ve used and takes me about 30 seconds to update after each trip.

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  7. Capt J

    Capt J Senior Member

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    That is NOT a fuel gauge. That is how much fuel the engine is burning which is why it is fluctuating at idle. There was gauge data in the CAT MFD, somehow, someone deleted it with a CAT computer. You need a dealer with the CAT computer to re-install the gauge in the CAT display (that knows what they're doing). It will look like a gauge and is usually on one of the pages that show 4 gauges on it.
  8. Capt Maritime

    Capt Maritime Member

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    Look at the photo of my STBD MFD upper right it is showing percentage of fuel level (77%) and is titled Fuel Level on the MFD. Fuel rate is showing on the lower left corner .7 GPH and is titled Fuel Rate. Am I missing something here?

    Also, I will check the MFD's tomorrow for one displayed as a gauge.

    I also track the fuel burned on the MFD's that so far has been very accurate each time I top off and reset the MFD's. Having a functioning fuel gauge as a reference when on long trips is good reference/cross check.
  9. Capt J

    Capt J Senior Member

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    Ahh I see it now.........chances are a bad connection, or the sender itself if it's floating up and down that much percentage. I'd lean towards the sender, hook the 2 sender wires together and see if it reads a solid 100%.
  10. Capt Maritime

    Capt Maritime Member

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    Capt J - thanks for the input. I'm heading to the boat this weekend and plan to further troubleshoot the connections and or the sender. I have done some research on the sending unit and have found old Cabo/Fuel Royce part numbers and the label on my sending unit Cabo P/N 30407.
  11. Pascal

    Pascal Senior Member

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    A gauge is a false sense of security. I prefer having a visual way of confirming fuel, either sight gauges for elevated tanks or a calibrated dipstick for under floor tanks.
  12. Capt Maritime

    Capt Maritime Member

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    Cap J - you are correct as well. I toggled through different screens and the fuel tank level percentage does show up on the screen with other gauges on it. So thanks for pointing that out.

    Pascal - I agree that a fuel gauge on a boat is a false sense of security, that is if it is the only thing considered to determine remaining fuel onboard. As mentioned previous, I track fuel consumed on the CAT displays on the bridge plus now I can visually see the fuel level with the percentage gauge on the bridge. It is a simple check and balance. I can also visually see the fuel level in the tank below the lazarette hatch when not underway.

    Fuel gauge stbd CAT display 1.jpg