difference between fuel sensors questions

[mellow65]

so i have a couple fuel sensor questions i'm hoping someone can help me with.

so for the sake of this thread lets just assume that i am swapping a large fuel tank out of a 1st gen legacy and putting in the smaller tank from the impreza or a 2wd tank (not really what's happening, but easier to picture this way )

so my big tank has 2 sending units, one on each side of the hump. each sensor measures around 50ohms empty and around 1.5omhs full. these sensors are wired in series so when you measure resistance going to the gauge cluster you get about 90+ohms empty and around 3ohms full.
the small tanks and 2wd tanks have one sensor. but according to the service manual the sensors should measure the same ohms.

so i guess the question is, does anyone know if there really is a difference between a small tank sending unit and a large tank sending unit. or i wonder if the gauge
clusters are just set up to read the different ohms for a pair of sensors rather then just one.

so then are 2wd gauge clusters different then awd clusters. but if so why hasn't this been brought up when people do awd swaps. just thoughts im having right now.

basically what i'm doing is swapping in a full legacy harness into another car and going to make the fuel pump and sensor work in the other cars gas tank

[Legacy777]

The FWD & AWD senders are different. As you described, the two senders on the AWD tanks sum up to the same overall resistance that is found on the FWD tank sender.

There's no difference in the gauge cluster on the first gen legacies between the AWD & FWD cars. Because of this, there's no issues when doing AWD swaps.

I'm not really familar with the "smaller" AWD tank with only one sender. However it should probably work similarly as the FWD sender.

[mellow65]

perfect thats what i was hoping. now over to the maket place for a WTB thread. or hit the JY.

the small tank from what i have seen came in early imprezas. my 93 awd has the small tank. think its like 11 or 12 gallons vs the 15 or 16 of the big ones. they both fit in either but after taking one out of a legacy that i was parting out, that thing was a pain in the ass to get out. i might think of swapping in the bigger tank if i ever need to take everything off my car for what ever reason.