New fuel sender stuck on full

[tomyoud]

Hi all,


I'm after a little advise.
I've just installed a new Wema S5 fuel sender (240-30 ohms) and connected the two wires up and the gauge reads full when I turn the ignition on.


So far I have disconnected the wires from the sender then touched the pink and black wires together with the ignition on and that reads full on the gauge, so I know it's not the gauge.
I then checked the resistance of the sender and it's reading 200 ohms (tank is about 1/4 full).


After routing though all my electrics, I have power going to the ignition post on the gauge, then pink on the sender post which goes down to the fuel sender, then a black wire on the ground post on the gauge going to a negitive bus (i think), also from that bus is another black wire which goes to the fuel sender too.


I've checked the resistance of each wire and only getting 0.002 so that rules out corrosion.


Is there anything I'm doing wrong?

[whiskylee]

This video might help

https://youtu.be/CrEASnoY2_w

[GuyC]

Have you an American sender and a European gauge?

200 ohms at 1/4 full sounds like an American sender.

[paintman]

Looking at the Wema site there are 2 versions.
0-190 ohms or 240-30 ohms
European one shown as 0-190 ohms.
American as 240-30 ohms.
https://wema.co.uk/products/fuel-sender-s5-5-bolt

[whiskylee]

The video I linked in explains the USA Vs Europe sender / gauges [emoji106]

Originally Posted by paintman

Looking at the Wema site there are 2 versions.
0-190 ohms or 240-30 ohms
European one shown as 0-190 ohms.
American as 240-30 ohms.
https://wema.co.uk/products/fuel-sender-s5-5-bolt

[Last Tango]

Check the instructions carefully.
I think there's something stupid about Wema gauges....ie pink is ground and black is the sense wire....could be wrong but my ageing memory's twitching with this one.

[breezeblock]

check that the float isn't getting held up by the stand pipe I had this with 2 brand new sensors last week but was the opposite way round both port and starboard were held down by the Flexi stand pipe

[GuyC]

Originally Posted by Last Tango

Check the instructions carefully.
I think there's something stupid about Wema gauges....ie pink is ground and black is the sense wire....could be wrong but my ageing memory's twitching with this one.

Correct and I've recently been confused by it as well. From the Wema website, the black is the sender and the blue is the earth.

[tomyoud]

Thanks for all the replies
GuyC - I'm pretty certain I've got an American Gauge, I disconnected the wires I connect to the sender and touched them together with the ignition on and spikes to full, then empty when not which looking at the Wema website suggests that it's an american gauge. https://wema.co.uk/pages/how-to-test-your-gauge
This is the gauge I have https://www.force4.co.uk/item/veethr...Fuel-Gauge/9F9
But it's made by teleflex



The looked at the video that whiskylee posted, the only thing that isn't the same with my wiring is that the earth from the sender goes to the negitive bus instead of the ground on the back of the gauge....I might try that when it's not raining

[GuyC]

Originally Posted by tomyoud

The looked at the video that whiskylee posted, the only thing that isn't the same with my wiring is that the earth from the sender goes to the negitive bus instead of the ground on the back of the gauge....I might try that when it's not raining

I wouldn't have thought that terminating the sender -ve at the -ve bus would be any different to doing it via the -ve on the back of the gauge. They all go to the same place. It's worth a try though.

Does the light work?

You could try and temporarily rig a supply to discount getting your wires the wrong way round.

Bloody electrics!

[paulbrown22]

I can try to check mine later on if needed - I fitted a new (US-spec) KUS/Wema sender and one of those exact Teleflex/Veethree Amega fuel gauges from Force4 last month to my little TomKat RIB, to replace the original ones from 20 years ago that had given up quite a while back.

[tomyoud]

paulbrown22 - that would be great if you can


GuyC - yeah that was my next step and hope I can rule something out, it was working perfectly fine with the old float arm sender but changed it because the float wasn't floating very well anymore
Maybe it is something with the wiring....the old sender just had -ve grounded to the sender itself

[tomyoud]

So after a little playing around, I sorted it.
GuyC was right, I had a european guage....even though it was made by teleflex (who I thought only made american guages). My own fault I should have checked the sender before ordering one.

Just ordered the veethree guage from Force4 and fitted hooked it all up.