electrical question for ppl REALLY sharp
 

I am putting an 1uzfe in my 92 toyota truck. I am also using the lexus dash. the swap post here.

https://www.yotatech.com/forums/f161...rv-2wd-286903/


My question is with the fuel sender. two different set ups and im trying to figure out if there is any way to make this work!

lexus sender is the first photo, it has 3 wires

toyota the 2nd with two wire.

Any advice?

I was reading through your swap before, nice work. It's possible you could get "a" reading, probably not anything exact but maybe enough to know when you're approaching empty. The Lexus uses a potentiometer, the truck uses a rheostat, or variable resistor. These are the same concept except for the number of terminals used. Of the three wires in the LS, it appears the two leading to the cpu are signal wires, the reading from the center wire to the green wire would also vary, but in the opposing direction. If resistance increased between purple and yellow as the tank filled, it would be decreasing between purple and green. Where does the green wire go in that diagram?

From a quick search it appears ohms in the LS unit are ~300, ohms in the truck are about ~100. So even best case I don't see a way to get the gauge to work as factory without replacing the sending unit. If you play around with some alligator clips and see what you can get for readings you might be able to get an approximate gauge by splicing the orange wire to purple, and brown ground to yellow, or vice versa, (assuming the truck doesn't ground to where it bolts into the housing which it very well may, in which case you would simply short one side to ground). There is of course a risk that the cpu would be damaged by this trial and error method. You might also try bypassing the cpu in the LS dash and tapping into the gauge directly. Because of the different resistance in the sending coils your needle will either never reach full, or never reach empty even if it does work, but you would have an idea.

The surest way would be to mount the truck gauge somewhere, maybe one of the dummy cutouts that's not in use. Corax on here did a fiberglass dash repair and built a gauge cluster into that, other guys have done similar on the pillars. That's all I've got...

Get the Lexus sending unit.

Get a after market fuel gauge with sending unit

Either of these would be the easy way to go.

Both would need the sending units wired to the gauge.

well I have the sender out of the lexus, Im hoping the bolt holes match the toyota. I did connect the wires an everything is still working. The lexus is a side mount, the toyota is a top mounted sensor, but i think with a little bending i can make it work. now i have to drop the tank, and see if it will fit. might as well change the pump i guess while im in there.

Thanks for the input, sounds like this is the best option.

Create a false leg
.

http://blog.orlandoautomotivefamily..../Fake-leg1.jpg




Nope, didn't work.