Fuel sending unit???

Anyone with a Hannigan conversion with Aux fuel tank...

Picked up my trike this morning and even though the light on the control switch is off (green light) the fuel is transferring to the main tank.
I filled both tanks this afternoon and took about a 90 mile ride. I kept noticing my fuel gauge was not moving. when I got home I checked both tanks. The Aux tank was empty and the main tank was full to the bottom of the Tube.

Anyone have any input as to how your fuel sending unit is working? Also, should have had at least 120+ miles from the fuel in the Aux tank and I only had 90 and it was empty. Tomorrow I'm going to put more gas in it and check for leaks. Leaving for a trip on Tues and need to get this working correctly before hitting the road.

Sounds like a possible wiring problem...always on or maybe reversed?
My transfer switch shows a green light (VERY dim and hard to see) when "off". When on it shows a red light, again VERY Dim. I have forgotten the transfer a few times when riding and mine does one of two things.
1. Sometimes when it transfers to the front and it fills the front tank, it seems as though I am running on empty. The engine coughs and sputters like I've just run out of gas. I quickly turn the switch off and in a few seconds it smooths out and we continue on.
2. Usually when I forget, the front tank starts oozing fuel out under the cap and I get a strong gasoline smell and a crotch full of gas!
So what I do is this: When I am doing the transfer (while riding) I cup my left hand over the switch as a reminder that it is "ON" and keep it there watching the fuel gauge until it shows "full". I placed my switch just left of the filler cap where the wired headset connection used to be. I use Bluetooth and I coiled the OEM wired connection and have it placed under the ignition cover piece.
Between both tanks on my trike I get 260 or so miles. I never switch to the reserve tank so I am pretty sure I would get a few more miles if I did. We were in Louisville, KY this past weekend for STAR-B-Q. I filled both tanks across from the hotel and rode to our house in Rockwood, TN without a refill along the way.

Dennisgar: Had this happen to me also. Check your "Off / On / Reserve" valve under the left side of your fuel tank. As I remember the valve was half way between Off and On, and for some reason the fuel that was being consumed was coming from the extra aux reserve tank not the main tank. It had nothing to do with my 12volt control off and on switch.. When I pushed the valve all the way to the on position that solved the problem. Take a look it may be just that simple of a fix...

thanks for the feedback. I will check the on/off fuel petcock for sure.
As for the wiring, the dealer was on the phone with someone from Hannigan to double check all that and it's supposed to be OK... we will see. I have already had the gas overflow issue and now the lets move gas to the main tank while being in the off mode.
I will keep a very watchful eye on this for the entire trip.

Thanks again for sharing info.:clapping: