New MMDC and now fuel gage problem

[jwroblew]

Put a new MMDC in the boat and now the fuel gage does not read, always sits at empty. Back light work, sweeps when you run the gage test, but always sits at empty. I have read about calibrating it with a gallon jug for full and empty, do I need to do this? If so how do I do it, I know I pull it out for empty, put it in a full jug of gas for full calibration, but do I have to short wires or turn the key at a particular time, etc.. It worked before the new MMDC, and I can't even put the old one back in.

[jwroblew]

bump ???

[jkski]

Not sure if this is your problem or not however, I just had the same issue with the gauge on my 08 and after checking the actual gauge, sending unit, etc., it ended up being the float that went bad. If your set-up is the same as mine, which I believe it is, when you look at the sending unit, there is a metal ring bolted down to the top of the tank with about 6 bolts. When you remove those, you will pull up a long stem with a rubber float on it that is secured on with a snap-ring, Remove the snap ring from the end and slide off the float then put it into a cup of gas and see if it remains at the top or sinks....obviously it should remain at the top.
Hope this helps.