VDO fuel sender with L/R fuel gauge

[rick130]

Anyone able to make this work ? ('98 300Tdi)

It's been a while since I had the sender out and checked it, (over ten years :angel:) and IIRC the resistances were OK.

All I've done over the last decade is fill the sill tank and when the main gets below 1/4 I transfer across.
It's just annoying now that when I switch across to the sill tank I don't know how much is in it.

I'll fire off an email to LRA, but in the meantime does anyone have a workaround ?
Maybe a resistor inline, or something similar ?

TIA.

[bee utey]

You really need to know the resistance range of the VDO sender as installed as well as that of the LR sender before anyone can answer that question. VDO make senders in a range of resistances. On some of them you can flip the float to reverse the resistance direction, if that is what is needed. Once you have determined that the sender reads with reducing resistance on filling and what resistance is needed to read "empty" you can add a series resistor to match.

Oh and your fuel gauge may be very slow to react to sudden changes in resistance, switching over might take a minute or two to show the correct level.

[roverrescue]

Rick your fender gauge will range from 30 Ohm full to 240 Ohm empty.

S

[rick130]

Cheers fella's.

Just had a quick look and I'll have to retrace where the sender wires go.
I mucked around with the switch, (SPTT) one wire measures 90 ohms ATM to earth but it doesn't measure anything on the gauge when energised.
The other is a supply (common) and pump supply.