Fuel Gauge Frustrations - UPDATE

[Scuda11]

Hi all,<br /><br />I just replaced my sending unit, thinking that was my problem. Didn't work, so I started troubleshooting. I checked my voltage on the wire coming off of the ignition switch to "I" on my gauge and it was only about 2.5 volts. My ground on the sending unit looks good and my sending unit wire is new and hooked to "S" on the back of my gauge. It is a new Teleflex gauge too.<br /><br />My questions for the experts are:<br /><br />

• <br />
• 2.5 volts out of the ign switch, Is that normal?<br />
• I wanted to bypass the ignition and go straight to the battery (for trblshooting only), would that be ok?<br />
• Does my ground on the tank sending unit have to go to a certain spot, or can I ground it anywhere?<br />

<br /><br /> Thanks guys, I appreciate it.<br /><br />1983 200 hp johnson, 20 ft Proline C/C.

 

[JB]

Re: Fuel Gauge Frustrations - UPDATE

To Boats.

 

[Scuda11]

Re: Fuel Gauge Frustrations - UPDATE

Update: I did in fact actually get 12 volts out of the ignition wire. But I still cannot get it to work. Frustrated now. I bypassed just about everything, troubleshot each wire, tryed new sending unit, old sending unit, old gauge, new gauge, etc. <br /><br />I am not a wiring guru, but no idiot either but I might just stick with sounding stick. lol<br />

 

[ThomWV]

Re: Fuel Gauge Frustrations - UPDATE

Don't burn down the boat just yet.<br /><br />Check the resistance on the pink wire that runs from the sender to the guage. It should be low. Bet your's isn't. Fuel guages are really just ohm meters. As the float goes down the ohms go up and the needle in the guage goes down. Put a short in the wire and let it be somehow grounded, via water possibly, to the tank and you get a non-working guage. Try replacing the wire. If that doesn't work sell the boat. Oh, you have tried a new guage haven't you?<br /><br />I only ask because I end up replacing a fuel guage about once a year, and I have 3 of them. So they last about two and a half years in my experience, of course that's about how long the wire is good for too, in saltwater at least. <br /><br />Thom

 

[Scuda11]

Re: Fuel Gauge Frustrations - UPDATE

Hi Thom, thanks for the reply. I actually have a white wire coming from the sending unit, is that a big deal?<br /><br />I will try what you said, but I am not sure how to put a short in the wire.<br /><br />Geez, maybe I am a wiring idiot.......

 

[rickdb1boat]

Re: Fuel Gauge Frustrations - UPDATE

I'm_a_learning <br /><br />Thom is not saying to short the wire out. He's saying that it could HAVE a short in it and be causing the problem. That's why he suggested replacing the wire. Color does not matter(Although most sending unit wires are pink), if it goes from the sending unit center terminal to the "S" on the gauge, as it should. Ground the sending unit to the engine block. Purple wire(Ignition wire) to (I) on the gauge and it should work. If not, try another sender or gauge.

 

[Scuda11]

Re: Fuel Gauge Frustrations - UPDATE

Thanks Rick. I am set up that way, with the exception of grounding to the eng block. I will try that, thanks again guys.

 

[Scuda11]

Re: Fuel Gauge Frustrations - UPDATE

OK Rick, semi-stupid question to follow:<br /><br />Where on the engine block should I ground it? Its a bout 9 ft from my tank, is there a ground wire already headed to my block?<br /><br />Thanks again, sorry to be a moron about this, Sparks, Fuel and I have never been close friends.

 

[Bayrider]

Re: Fuel Gauge Frustrations - UPDATE

I,m_a_learning <br /> Try this site, it might help. <br /> www.tflx.com/tech.html

 

[rickdb1boat]

Re: Fuel Gauge Frustrations - UPDATE

There should be a ground wire that goes to the block and the fuel tank filler. This grounds the filler and prevents static electricity from causing a problem when you are fueling up. You may not be able to see it, but it should go to both. If there's already a ground wire their, use it. It should be ready to go. Easy to check with an Ohmmeter and some extra wire to see if it's good.. Of course, the gauge also needs to be grounded through the system, but you can pick that ground up under the dash by tagging into another ground wire or coming off the terminal block ground if you have one.<br /><br />BTW- If you have everything hooked up, just remove the sending wire from the sender and ground it with the key in the on position. If your gauge is good, it should go to full..

 

[Scuda11]

Re: Fuel Gauge Frustrations - UPDATE

Awesome guys, thanks, I will check and re-post back, thanks again.

 

[Scuda11]

Re: Fuel Gauge Frustrations - UPDATE

UPDATE: I tried what you said Rick, I grounded the "S" wire with key on, did not go to full. I know the gauge works, but I bought a new one anyways, still nothing.<br /><br />This is what I have for wiring:<br /><br />From sending unit, the sending unit wire, and a ground that is split, one wire goes up to the top of my fill hole and is screwed under the fill hole mount, other wire goes to what appears to be a ground on my fuse board thing under the center console. <br /><br />From ignition, purple wire (then crimped into a white one, but still getting 12v out of this) Which goes to my "I" on my gauge. The ground on the back of the gauge says it is only for the light, but I hooked it up anyways. That ground wire is coming from the same fuse board under CC.<br /><br />Could it be that my ground on the "fuse board" is bad? If so, how do I check that, what OHMS should a ground wire show? ZERO?<br /><br />Thanks all in advance.<br /><br />Still a Learning

 

[Richok]

Re: Fuel Gauge Frustrations - UPDATE

I may not be understanding where you have your ground. On my boat there is a ground wire running to the filler neck but there is a splice to the sending unit because I have a rubber hose between the filler neck and the tank.You might try taking the sending unit out of the tank. Hook it up normal way to guage and bypass the switch temporarily (hook your power to battery just to test. This is the way I found my problem. If you haven't gone the website bayrider suggested I strongly recommend it.

 

[Scuda11]

Re: Fuel Gauge Frustrations - UPDATE

Hi Guys.<br /><br />Hopefully a stupid question here: I tried test as mentioned on the website as well as by you guys in here. Hooked up on my bench to a good battery. power to "I", negative to "G", grounded out the "S" terminal and gauge pegged to past full as it should. NOTE: I also tried my old gauge, that worked fine too. Problem is I tried it on the boat this morning and didnt work, so I am trying to test the gauge again.<br /><br />How do I get the gauge off of PAST FULL to re-test it?<br /><br />Thanks guys.

 

[Boatin Bob]

Re: Fuel Gauge Frustrations - UPDATE

It sounds like you have a ground problem, do you have a multi-meter, if so you want to hook up between the eng block (anywhere you can get a good connection) and then hook up to your ground wire at the tank and see if you have zero ohms, if not then you have to see where the break is in the ground wire. Or as suggested above you may have an open sending unit wire.<br /><br />Try tapping the gauge lightly to see if you get the needle to reset, worst case is you may have to open up the gauge to manually pull the needle off whatever it's hanging up on.

 

[Scuda11]

Re: Fuel Gauge Frustrations - UPDATE

thanks Bob, yes I do have one. When I did this test, I brought out my test battery and used that to bypass everything on the boat. For a ground (on sending unit and gauge) I ran seperate wires for each to the neg post on my battery. Ran a wire straight from pos post to "I" on my gauge.<br /><br />I will try the opening up on my old gauge.

 

[Boatin Bob]

Re: Fuel Gauge Frustrations - UPDATE

OK...you know the gauge works when you did the bench test, you then said it dodn't work when you put it in the boat, how did you test it? Did you ground out the S term at the gauge or did you ground out the sender wire at the tank? I know in your first post you said the sender wire was new but have you actually done a continuity test to make sure it's OK?

 

[Scuda11]

Re: Fuel Gauge Frustrations - UPDATE

Ok, a little update: I hooked it all up on the boat, but using my bench battery. Got it working!!!!<br /><br />However, when I try to use the wires on my boat, no go. I know it is a ground, b/c I am getting 12 volts on my ignition wire.<br /><br />Question is this: I have a ground like I said up from the sending unit, up my fill tube and screwed under my fill cap. Then it goes to my "circuit board" I guess it is, which is also where my gauge ground goes. They are screwed into the bottom, into 2 different screws. This is obviously where my problem is, but how do I know if the board is grounded, I mean how can I check it?<br /><br />I am getting there guys, thanks for bearing with me.

 

[rickdb1boat]

Re: Fuel Gauge Frustrations - UPDATE

does everything else that requires a ground work? If so, your terminal board ground is good. I would suspect that there is a break in the ground wire from the sender to the gauge. Any way you can run another one? Another test to confirm this would be to just hook up a long ground wire to the sender and however you can get it to the gauge, hook it up and see what happens. Even if you have to run it across the floor of the boat to the gauge. Just for test purposes only. Also, try running the ground wire from the board to the gauge ground and see what happens

 

[Richok]

Re: Fuel Gauge Frustrations - UPDATE

I don't know if you have a ground that it welded to the tank or not. I have one on mine. I haven't had it out since I put a new sending unit in it, thought it was working, kind of like your situation. Took it out yesterday and guage wasn't registering. I took Rick's advice and ran wire across floor to my welded ground to the G on the guage.Guage didn't work went straight to the screw on base of the sending unit and it works with boat wiring. The gasket under the sending unit is causing it not to ground even with the screws in the tank. Sounds crazy to me but it works. You might try it if you have a similiar set up.