Fuel Gauge Sender Again

[rickalan35]

Hi,

My boat splashed down yesterday which is late I know, but the water is still at spring flood levels here. Higher than I can remember in the forty years that I've been around the Rideau. After a few hours of cleaning off the winter storage grime, I ventured to take a moment to check the port side fuel gauge sender (located under the infamous galley sink double floor) and now I need some help. I know that this topic has been discussed here recently but I still need help. My sender has only ONE wire connected to it. Is that the way it should be? Hope not because if I'm missing a wire, my senders might just function properly if properly connected. Thoughts?? Big D? P-Fish ? Anyone? Thanks, Rick

[mikeandanne]

Rick all of the senders on our boat a 78 f32 are one wire only--- there are four tanks all original and the same as the wiring diagrams---- Mike

[prowlersfish]

One wire plus a ground . You can have ground wire on the sender and the tank should have a ground wire elsewhere on the tank.


Are you having a proplem ?

[rickalan35]

Hi Mike,

Thanks for the reply, much appreciated. Well, I suppose that wasn't good news.

Big D at one time inquired if the "ground" wires were re-connected when my tanks were re-installed. Is this single wire the "ground" wire? If not, where are the ground wires located?

[rickalan35]

Just got Prowlers reply. Well, that's good. I wonder where to look for that ground wire connection. I wonder where it terminates.

[prowlersfish]

The tanks normally Have a tab for the tank ground on top . I also like to have a separate ground to the sender in addition to sender wire it self . You can hook a ground wire to one of the sender screws

[prowlersfish]

the Ground wire should go to a ground buss .

[rickalan35]

ProwlerFish, If I wanted to hook a new ground wire to the sender, I assume that I would run a wire from the terminal to any convenient grounding point of my choosing?

I suppose that simply running a "test" ground wire would possibly be a good indicator, if the results produced a readable gas level on my control panel.

[mikeandanne]

Maybe I should have explained further, the senders themselves only have one wire that goes to the gauge ----the senders are grounded thru the tank itself----on mine the grounds are on the opposite end of the tanks---try to look for the ground on the tank, maybe they are not connected properly---Mike

[prowlersfish]

The tank should be grounded and that should ground the sender . But in most cases there is a redundet ground( extra) grounf wire on the sender/sender screw . And yes you can test to see if thats your proplem with a jumper ground wire .

[rickalan35]

Hi

Okay sounds good. My sender has an second terminal with nothing attached to it. I will run a test wire from that terminal to a convenient grounding point and see what happens. I will also get to the front of the tank and look there (as Mike says) and attempt to locate the tank's main grounding wire. Thanks Guys!

I spoke with our marina mechanics and they state that in 2004, when they sent my two tanks out to be "coated" inside they did NOT removed the sending units first.(They must have good memories) - On my request, they phoned the Toronto company that recoated the inside of my tanks and they indicated that they usually remove the sending units before processing the tank (but not always).

I may indeed be the lucky guy who has a sending unit mummified on the inside of the tank like a stalactite.

Rick

[prowlersfish]

If they did not remove the senders then they are coated too

[rickalan35]

Yep

[Big D]

As Paul mentioned earlier, it is best to ground the sender separately as one should not be using the bonding circuit as a DC ground for a peripheral but it gets done all the time. A direct ground to the sender will also provide a better electrical connection given that you should be coating the sender's mounting screws, there's a gasket between the sender and the tank, etc. The tank is bonded/grounded for safety reasons and should not be used to ground a device.

If you can't find the tank's bonding wire, you can do a continuity check with a meter. One probe on the tank and the other on another bonding point; battery, engine block, etc (if done right), or thru-hulls if bonded and you should get continuity. If you don't, the tank is not bonded/grounded and is something you should remedy.

[rickalan35]

Okay Big D, thanks, thanks and thanks.

Will report back here the results. Life would be a lot more convenient with working fuel gauges.

Absolutely teeming rain here this evening with the result that most of the boats on my dock developed leaks (even those that don't leak). My tricabin did quite well and so I was really pleased. I've still got one that leak by the starboard side, aft cabin window that has been driving me nuts for three years. All other leaks have been defeated - but not that one.

Cheers

Rick