Questions about checking sending unit wiring

[Steve500dancer]

I am having trouble with my fuel gauges. I have three tanks, PORT STARBOARD AND CENTER. I have only one gauge and a three on position switch. When I turn on my ign and turn the port side tank switch on it pegs the gauge, when I flip the switch to starboard it also pegs the fuel gauge. When I flip to center, the gauge goes down to empty. I have located two of three fuel tank sending units. (port and center. The pink wires a little loose and the port tank ground had a circular terminal. The sending unit had a spade. Tonight I changed that out. The switch is obviously working because it is flipping between all tanks. The gauge is also working because it is quickly pegging on the port and starboard tank and dropping to empty on the center tank.

I could understand if one or even two of the sending units we're bad but 3 sending unit seems to be a stretch to me.

I figure it has to be a bad wire. I am going to start but disconnecting each sending unit pink wire one at a time to see if that is shorting something out. How can I test the wires or sending units using my multi meter or a test light or my toung and a glass of water?

I would also like to figure out where in the heck the starboard fuel tank sending unit is. They are not where the manual shows them and I have been through all the picture of where the carpet was out and all the access panels are. I will post a couple of pictures of the 2 of 3 sending units and maybe someone can give me an idea of where it is before I go to gutting up my new hardwood floor oh it is a 1996 500DA

Any help on this would be greatly appreciated

Thanks in advance
Steve

 

[Steve500dancer]

Sent from my iPad using Tapatalk HD

 

[Steve500dancer]

Update on this, found the third sending unit. It was right where sea ray customer service said. It was under the port salon. I have also replaced the gauge and now my port and starboard tank show 3/4 full each and the center tank is showing below empty. I a, going to check the tanks this week to see how accurate the port and starboard gauges by removing the sending units this week and measuring what I have hyphen and seeing if the sending unit when moved will move the gauge. I am also going to jump the center tank unit with the port side unit with a jump wire and see if the gauge shows anything. If all that works like I am hoping I will have to replace the sending unit on the center tank and away I should go.

I will keep everyone posted


Steve