Greetings from Sunny Florida 78 corolla work in progress trying to get fuel gauge to work looked at old sending unit all rusted up looks like simple setup 1 wire to top of unit but the ones I looked up to order new look different with 2 wires I don't know  if thats the wrong sending unit cause It was just laying in trunk when I bought the car the Haynes manual say I believe a yellow wire with red line wire which i don't find in harness on rear of trunk also there a wire showing YL Wire for low fuel level going to sending unit any ideas new to this old school ke30 ?

Hi David,

              It's a sad story with fuel level sensors in olde Corollas.  They are not particularly accurate or linear, in their display.  I've tried all sorts of things over the years.

Best bet is to find something similar, that will fit in your tank, with it's float; & then massage the resistive signal at the dash end until it reads close to what it should.  The single biggest problem I've come across with these fuel gauges, is the DC power supply regulator, fitted to the back of the dash unit.  They regularly burn out.   a regulator is required, as the 12 volt supply can go up & down, & the gauge would like increase of decrease.

The regulator, is usually a 6, 7, or 8 volt DC one.

I'd pull out the dash, & with the fuel sendor unit disconnected; measure the DC supply, with a multimeter, at the dash.  I think I covered this in more detail once, somewhere on here.  I'll see if I can't find it, & add a link in my reply.

https://www.rollaclub.com/board/topic/76685-cleaning-inside-of-fuel-tank/page/2/#comment-723267

Cheers Banjo

Edited December 1, 2025Dec 1 by Banjo

Thanks for the help I have the dash out but can't seem to get it out all the way out to see how's it connected to cluster those it just turn to loosen or pull off don't know how's it's connected can't see do you happen to have a picture of rear of cluster gauge don't want to break anything thanks in advance 

Hi David,

               Is your dash instrument cluster, similar or like this one I found on ebay, that has a number of photos, including the rear ?

https://www.ebay.com.au/itm/326234860459

Cheers Banjo