Never seen this type before, maybe others are familiar with it.
I just bought this as replacement for a 2006 Freightliner M2. The rod is non-magnetic stainless steel. The float rides on the rod and is magnetic, it will attract a screwdriver held next to it. On my analogue multimeter, the two leads have 28 ohms across them when float is all the way up (full tank) and the resistance increases linearly to 255 ohms when float is moved down. so it looks like there is a potentiometer housed inside the rod and the float moves the wiper.
The senders I have encountered before have the pot exposed to fuel.
The two leads coming from the instrument panel and going to the sender have 12v across them when not connected to the sender. When I hook up my analogue multimeter on the 250 ma DC scale across the leads from the gauge, the short-circuit current is only 30 ma. So the source impedance is 400 ohms, considerably larger than 255 ohms. The circuitry inside the instrument panel processes the signal from the sender and drives the stepper motor for the gauge.
I just bought this as replacement for a 2006 Freightliner M2. The rod is non-magnetic stainless steel. The float rides on the rod and is magnetic, it will attract a screwdriver held next to it. On my analogue multimeter, the two leads have 28 ohms across them when float is all the way up (full tank) and the resistance increases linearly to 255 ohms when float is moved down. so it looks like there is a potentiometer housed inside the rod and the float moves the wiper.
The senders I have encountered before have the pot exposed to fuel.
The two leads coming from the instrument panel and going to the sender have 12v across them when not connected to the sender. When I hook up my analogue multimeter on the 250 ma DC scale across the leads from the gauge, the short-circuit current is only 30 ma. So the source impedance is 400 ohms, considerably larger than 255 ohms. The circuitry inside the instrument panel processes the signal from the sender and drives the stepper motor for the gauge.