Low fuel warning sender?

Mr Gazza · 17-06-2020, 05:51 PM

Okay, so I bought a nearly new sender some years ago from Drumnagorrach, installed it and tested the range with a ready can tucked in a pannier.

The light came on at about 120 miles if I recall, but that was the last and only time I ever saw the light on. I have since had the tank empty and I don't think the light has come on. I have assumed that it doesn't work.

So I've just acquired a new one and thought I had better just test to see if it isn't the bulb gone before I get the new sender wet. Yes the bulb is good, I can light it by feeding the correct pins in the instrument nacelle socket. And I can also light it by poking a "staple" of wire in the socket at the sender end, so I have cable continuity as far as there at least.

But if I plug the new sender in, external to the tank, I get nothing, surely it should light the bulb if it's out of the tank and bone dry? Or is this not how they work? Obviously the pump is not connected for this test, but that's a completely different circuit, besides I lit the bulb by bridging only the sender cables.

I have also tested the continuity of the signal wire either side of the plug/socket to make sure there is contact. Come to think of it I didn't test the live, so that's the next thing.

I also need to drain the tank with the ignition on to see if it lights with the old sender, just to make sure.

Am I missing something here? Does the sender have to be in the tank in petrol?

17-06-2020, 05:51 PM	#1
Mr Gazza Lord of the Rings Join Date: May 2013 Location: Norwich Bike: M900sie Posts: 5,806	Low fuel warning sender? Okay, so I bought a nearly new sender some years ago from Drumnagorrach, installed it and tested the range with a ready can tucked in a pannier. The light came on at about 120 miles if I recall, but that was the last and only time I ever saw the light on. I have since had the tank empty and I don't think the light has come on. I have assumed that it doesn't work. So I've just acquired a new one and thought I had better just test to see if it isn't the bulb gone before I get the new sender wet. Yes the bulb is good, I can light it by feeding the correct pins in the instrument nacelle socket. And I can also light it by poking a "staple" of wire in the socket at the sender end, so I have cable continuity as far as there at least. But if I plug the new sender in, external to the tank, I get nothing, surely it should light the bulb if it's out of the tank and bone dry? Or is this not how they work? Obviously the pump is not connected for this test, but that's a completely different circuit, besides I lit the bulb by bridging only the sender cables. I have also tested the continuity of the signal wire either side of the plug/socket to make sure there is contact. Come to think of it I didn't test the live, so that's the next thing. I also need to drain the tank with the ignition on to see if it lights with the old sender, just to make sure. Am I missing something here? Does the sender have to be in the tank in petrol? __________________ Last edited by Mr Gazza; 18-06-2020 at 07:56 AM..