Wiring fuel sending unit

I'm in the process of restoring my 1981SN and am having problems with the fuel sending unit. I've drained the tank two times, removed and replaced the existing sending unit. When I turn on the ignition the gauge pops up to the empty point. While out of the tank, I moved the actuating arm up and the gauge registers as it should. Put it in the tank, properly, pointing in the proper direction, fill the tank with fuel and get the same results. I have an aluminum, 31 gal. tank, 12" deep. Black wire attached to the top of the sending unit, gray or pink wire hooked to the clip of the sending unit. The sending unit is a Moeller electric sending unit, SKU#MOE 025722-10.1 as advertized on Wholesale Marine. A guess, could the sending unit be touching the bottom of the tank? I just thought of that! Any help would be appreciated.

Thanks for the info. The Pink was hooked to the ground sideclip and the ground was hooked to the sending side. Reversed the leads and tried it, still the same. ? I'm back tracing the wiring off the latest schematic I have which is 1984.

rapok4 wrote: Double check you have a good ground. Common problem is loose or missing ground.

Agree.

With everything still installed, remove your pink wire, and touch it somewhere else on the metal ring that the black wire is attached too. This should peg your gauge to full.

We'll see where we go from there.

Well, that confirms that your gauge is good, and that you have a good ground.

Unfortunately, it means there is something wrong with the sender or the way it's installed.

Is the the type with a float and a wire arm that kind of looks like a little toilet bowl float?

Had someone working on my boat. They removed the tank to clean it out. Have no idea as to weather the unit thats in it now is a new one or the original. When I got the boat back, it wasn't even wired. Long story with this guy. I've removed it and reinstalled it carefully two times. It even worked out of the tank. I moved the actuating arm up and it moved the fuel gauge up. Thats why I'm wondering if the arm is hitting the bottom of the tank keeping it from moving. I'm a GC with 40 yrs of experience so I know a little bit about what I'm doing. Can I pull the tank out carefully with the fuel in it and remove the sender again? How do I send you a picture on the Forum?

Now that I relook at the sender pic,isn't that phillips head screw on the far side,the ground???

Yup, the OP said an aluminum tank, that's my plastic one.

The Original Poster has to remove the tank to get the sender out? I had enough clearance with the tank in place, but a little bigger boat I guess.

Wondering if the ground wire for the stern light is being mistaken for the actual ground wire. Without the actual ground also connected, the stern light ground would be a path to no where.

To post a picture, don't use the "quick" reply box. Find the other Post Reply with the little diagonal blue arrow. Click on that one, and choose the icon for posting a pic. Will be easy from there.

It's tight, but I have had it out. Did the picture come through? The boat is trailered, in my shop. The arm swings to the port side of the tank. The starboard side has a baffle in the tank to keep down sloshing. Don't know if the correct sender is in the tank. I could remove the screws and lift the sender up. I have about two to three inches of clearance at the stern.

Ground wire is probably just daisy chained off the stern light. That's ok.

From another thread:

backfoot100 wrote: ... I might suggest that you check out wemausa.com and look at the SSS/SSL senders. Much more sturdy than the factory wiper arm type unit. A little more pricy but well worth it in my opinion.

I haven'taken time to read all these posts, but I think you originally mentioned a gray and pink wire on the center post???? The gray doesn't belong there. That's the power to the stern light. And the green wire bonds (grounds) the fuel fill.
Art

Not the problem, Thanks

Best news I've had yet. Out of the tank it looks new, not tarnished. The float is a black substance, doesn't look like cork. It looks exactly like the picture I posted which was from Wholesale Marine supply. That's why I'm buying a new one and replacing it as you said. How's that old saying go, The third time is a charm! Let's hope so? Thanks again!

Brian wouldn't that peg the gauge full?

Could just be a defective float. Put it in a gas can.

So for anyone following this thread or has found it as a search result, the problem was the sender arm was stuck against the bottom of the tank. He decided to make a separate thread explaining this () but after bending it up a little everything fine works fine.