Gas Gauge Failure

[Michiman]

Filled up both tanks. Launched. Main tank shows full, flipped switch to Aux. and needle fell dead to past E. Where's the fuse? Or did the switch go bad. 2001 Champion 223
I am running up and down the Saint Mary's River the next 2 days and 250 XB is thirsty.

[wavewhacker]

If you can’t find the problem, I’d run off auxiliary then switch to main till I find the problem. I guess that’s possible ? I only have one big tank. Might check the sending unit in the auxiliary tank. Those kind of problems bug the hell out me till I fix them ! Good Luck ��

[Tx Champ]

If you are handy with a volt/ohm meter, here are a couple of documents that will help. Since the gauge is working in the main position, it possible that it could be the switch, and I'd certainly check that first, but bet it's either the wiring between the switch and sending unit for the Aux tank or the sending unit on that tank.

https://www.v3electronicsusa.com/wp-...uel-Sender.pdf
https://www.v3electronicsusa.com/wp-...evel-Gauge.pdf

On the 2nd link, there is an illustration near the bottom right of the page for a dual gauge set up. A dual tank set up is very similar in that your gauge will be coming off the center connection to the switch and you'll have 2 sending units on the outsides to switch between. If you have any questions, holler back with which boat you have and I'll see if I have the wiring diagram for it.

[Michiman]

The needle fell past E and will not move toggling switch from main to aux. Just dead

[Tx Champ]

OK, so I understand the gauge will not work on either switch/tank position. What year and model is your Champ?

[Michiman]

2001 223 Elite DC

[Tx Champ]

OK, since neither tank is showing fuel level, I'm going to assume that the wiring to the senders at the tanks are good. So we'll troubleshoot from the switch to the gauge. First, check all the wires going to the back of the gauge have not come off and are tight. Try to trace them back to their origin and make sure they are connected there as well. If you don't have a volt meter, you can get a test light at an auto parts store for a little of nothing.

With the ignition switch on, check for 12v on the "I" terminal on the back of the gauge (purple wire). You can test to the black wire which should be grounded. If you do not have voltage there, trace the purple wire back to the ignition switch. If you don't have votage at the switch with it on, the ignition switch is bad.

If you do have voltage at the back of the gauge, disconnect the "S" wire (Pink) on the back of the gauge. Take a short piece of wire and while holding it to the "I" terminal, bump the other end to the "S" terminal on the back of the gauge. The gauge should go to Full when you do that. If not, the gauge is bad. You may need to get a helper to watch the gauge for that step.

If the gauge is good, trace the Pink wire back to the fuel selector switch. When the ignition switch is on, you should have 12v on the Pink wire coming from the gauge. Then you should see 12v appear on the other terminals of the switch as you switch it back & forth. If you don't, the switch is bad.

If the switch is good, you're going to have to check the wiring from the switch to each of the sending units. I really don't think this will be the issue since neither tank is showing fuel. From the switch to the gauge is all that both have in common.

I've tried to explain as well and simple as I can. Having an electronics background, I may take some things for granted. So if there's something you don't understand, maybe we can get on a phone call when you have a meter or test light and are ready to wallow around in the floor of your boat ...

[Michiman]

Thanks. I will follow your instructions when I get back down state and HOME tomorrow. Wind rub, wet, low weigh in. But it was funny watching sleds bouncing and banging waves while I had the true smooth ride.