in progress: optitron gauge in '03-'04 corolla w/working fuel gauge

[shikikanzero]

so through the research ive done, ive found that the optitron gauge from the 2005+ LE plug and plays with the 2003-2004 corolla, but a couple of extra lights and the fuel gauge doesnt work. from what i know the fuel gauge works from the fuel sender sending a resistance reading to the gauge. i want the optitron gauges in my car bad enough so im taking it on myself to solve the problem. i did a reading of the fuel sender resistance from a near empty tank (last line) to a right below half tank (1 line below half). the readings i got was 107ohms for empty and 67ohms at under half tank. so the wiper on the fuel sender reads a low tank as high resistance and a full tank as low resistance. what i have to do now is find a reading from a 2005+ corolla and find what the empty resistance reading is. if its just a lower resistance i can add in a resistor inline from the fuel sender to the gauge but if its at a higher resistance or reversed (ie full tank = high resistance/low tank = low resistance) then im going to have to look into ways of switching the fuel sender unit. anyone want to chime in with their input?

[invader]

Full = 17 +/- 2.1 ohms
Half = 40 +/- 4.5 ohms
Empty = 120 +/- 6.5 ohms

Your numbers make sense. Fuel level can go down well below last line when it's just about completely empty. All Corolla CE LE S and XRS models produced from May 2004+ have the same fuel gage sender assembly # 83320-02010.

Originally Posted by shikikanzero

... a couple of extra lights and the fuel gauge doesnt work.

A couple of extra lights?? It might need a moment to adjust itself.

[shikikanzero]

wait the fuel sender unit is the same between the 2 revisions? i was reading that from 2005 something was redesigned in the fuel tank or something. oh well maybe ill try asking someone in my complex that has a 05+ le to let me test it out and ill offer him like $15 in gas or something.

and the extra lights i was referring to were things like tire pressure sensor and all that other stuff that i dont think were even options in the pre 05 models

[invader]

Actually, Corolla's produced between Jan 2002 and May 2004 had fuel gage sender assy # 83320-12640... All Corolla CE LE S XRS models produced from May 2004 to Dec 2010+ have sender # 83320-02010.

http://www.toyodiy.com/parts/

http://www.toyotapartszone.com/oem/t...320-12640.html

http://www.toyotapartszone.com/oem/t...320-02010.html

[shikikanzero]

so im unable to get my hands on a 2005+ corolla sending unit to test, so i came up with an idea of using a 1k pot to simulate a sending unit to find the operating resistance range of the optitron gauges fuel gauge. the gauge should hopefully be in the mail later today so well see