Fuel Sender Help

[boatnamesue]

Installed my new tank yesterday, now working on the console's wiring total makeover.  The tank fabricator offered me a WEMA fuel sender at less than half of market price, couldn't pass it up.  Hooked up the sender per instructions, very simple.  2 wires, pink wire to common ground and black wire is gauge sender.

When I finished connecting all of my engine/tach/control harnesses I put the engine on flush and started to do an overall check of all electronics.  At least 18 gallons of fuel in new tank.  Fuel gauge reads "E".   Thinking I might have reversed the ground and sender wires tank side, I disconnected both sender ground and gauge and swapped.  Still reads "E". 

1st pic below just shows you the basic type of analog fuel gauge.  2nd pic is underside with black lines to the 3 terminals indicating Ignition, Ground, Sender.  I took the pic after removing the sender wire, that's why you see no connection made on this terminal. 






The red wire at top of pic is fuel gauge power wire.  The other end is a bullet connector into the tach harness, via the yellow accessory lead (same connections as previous fuel sender).  After leaving the boat it occurred to me I should have checked for power from this yellow accessory.  However, the tach was receiving power, which is probably why it didn't occur to me to check yellow lead for power.

WEMA's troubleshooting for testing sender operation is as followed:
*Disconnect the sender wires at the sending unit.
*Connect the 2 wires to an ohmmeter or multimeter and set signal to resistance.
*Take measurement of the sender at empty and full positions by removing the sending unit from the tank and then manual operate the float by hand.
*For American Standard, the meter will show 240 ohms at empty and 30 ohms at full.

When I head back to back this evening I'll double check gauge is receiving power from tach harness.  If so, I'll perform the test procedure above.  If anyone else has a different idea, please let me know.

[Capt. Bob]

I posted this 2 days ago.

http://classicaquasport.com/smf/index.php?topic=14243.msg141533#msg141533

I cannot see your pic but....

Pink is industry standard for your sending wire. My WEMA gauge did not have a pink but rather black (ground) and white or tan (sender) IIRC.

First make sure you have the sender wired correctly and then follow the TS procedure in the link.

Power to the gauge (ign) is switched and should be available at the gauge when you turn on the key to "start". Check for 12volts at that terminal and ground. Check wire continuity and all connections.

Good luck.

[boatnamesue]

I posted this 2 days ago.

http://classicaquasport.com/smf/index.php?topic=14243.msg141533#msg141533

I cannot see your pic but....

Pink is industry standard for your sending wire. My WEMA gauge did not have a pink but rather black (ground) and white or tan (sender) IIRC.

First make sure you have the sender wired correctly and then follow the TS procedure in the link.
Power to the gauge (ign) is switched and should be available at the gauge when you turn on the key to "start". Check for 12volts at that terminal and ground. Check wire continuity and all connections.

Good luck.

Grainy pic, but you can see WEMA identifies pink as ground.  When I head back to the boat I'm going to pull the sender unit out of tank and troubleshoot from there.  Easiest way.  Thanks.

[Capt. Bob]

Well, it will function either way. The sender introduces a variable resistor to the fuel gauge electrical circuit. It (the sender) receives no voltage so it doesn't care which wire goes where.

Since the sender is new, you can "remove" it from the circuit by disconnecting both the pink and black sender wires. If you have power to the gauge and a good ground your gauge should read full (pegged really).  If it continues to read empty, you either have a fault at the power or ground connection or somewhere along the wiring to same or the gauge has given up the ghost.

Good luck chasing the gremlin.

[boatnamesue]

Ohm tested new sender, it was good.  The ground/sender wires that are butt connected to the senders pink/black wires are good.  Problem has to be with the fuel gauge or the power supplied to it.  On my checklist for tomorrow.

[wingtime]

just power up your gauges and ground out the sender terminal (S) on the gauge.  It should peg full

[boatnamesue]

Found the problem.  It was a ground issue.  That issue has its own thread:

http://classicaquasport.com/smf/index.php?topic=14296.msg141583;topicseen#new