fuel level sending unit

[guglielmo6160]

F31 fuel tank senders, anyone have any line on getting one, I guess Im having a problem with my sender in the aft tank, shows 1/4 to 1/3 and guess what,,,, empty, is there a way to cal? I dont think so,
any info would be great

[gjrylands]

No, there is no way to calibrate the sending unit. It will have to be replaced.

There isn't much to it. It is a reostat controled by a float. Universal sending units are available, but I don't know if they would be compatible with your fuel gauge.

[Dan Faith]

It depends on the sending unit. If you look at sending units on line they are for different tank depths. You set the depth on the float gauge based on the bottom the the tank, if for some reason the float is not dropping to the bottom the the tank it may be installed where it is resting against the side. The reheostat has the least resistance at full and is at the most at empty usually a faulty sender will break the wire and you will get an empty reading when the level drops below the break in the wire.

[kevin babineau]

if u do get an aftermarket sending unit i would take the extra time to hitch up the wires before u install it in the tank and test the system ...then remove the wire a install in the tank. i say this for 2 reasons one, is that for some reason i have put them in and it was wired backwards from the factory 2 just to make sure it all works right...to find out if ur gauge is working properly, from behind the gauge remove the wire that goes to the sending unit..the gauge should drop to E and then take a jumper wire and go from a good ground to the sending unit side of the gauge..it should jump to full...never should positive power be going to the tank...sounds silly but i have seen it...ps if u have a 2 gauge system the set up might be different

[guglielmo6160]

groovy, I dig,
Im now guessing my gauge is messed up, when I disco everythng it still stays at 1/3 not cool

[kevin babineau]

u have to turn the ppower on to the gauge and the gauge itself needs its ground with nothing going to the sender it should read empty...with the power on to it when the sender is grounded it should pin full

[davidsmith]

Check this out. Best i have used.
http://www.wemausa.com/

[guglielmo6160]

david ,, good link, thanks, reasonable as well, would anyone happen to know the length of this transmitter , before I take the old one out, , my F31 seems to have the original steel tanks, running port to starboard
thanks

[davidsmith]

The length is critical. Measure the outside of the tank and subtract at least 3/4 of inch to overall length to order. Best to measure from inside the tank straight down where the old sending unit is mounted and subtract 1/2 inch.

[gjrylands]

Removing the sending unit will not give you the length. The set up for Trojan's is a piviting arm with a brass float on the end of it. To get the length measure the inside diamiter. You can easily measure the depth on the end of the tank.

To check to see if your gauge is working, take the wire off the other gauge and connect it to the gauge you are checking and see if you get the same reading.

[guglielmo6160]

gerry, I wont be changing the transmitter with that type of level sensor, but rather the linear type

[gjrylands]

I thought you would use the linear type, that's why you want to measure the tank, so you will know which one to order. Measuring the end of the tank will be easier then trying to measure through the sending unit's hole in the tank. You won't need to remove the sending unit until you have the new one to replace it.

[davidsmith]

The reason I measured thru the sending unit hole is for an accurate measurement where the sending unit will be. If the tank is warped or there is a bulge in the bottom of the tank it will not show up with measuring the end of the tank. Been there done that.

[jwrape]

My Generator Tank sending unit is not working. I need to replace that one. That should be fun since it is wedged under the floor in the beldge where you can't get to the top of it....