Another fuel gauge not working… (1 Viewer)

[Imfafu]

New to me ‘72 55. Going through some immediate issues. Would love to have a functional gas gauge. I think I have read through maybe 20 threads on this issue. My float/sender is functioning properly (checked with ohm-meter) Contacts on the back of the gauge look clean, the ebrake and charge lights both work… none of the rest of the gauges work. I originally was thinking bad ground, but if those lights work, that wouldn’t be the problem right? When comparing the plug to the back of the gauges, the circled pin has no wire in the plug… should it?
Thanks, Matthew

 

[charliemeyer007]

You should look at the correct wiring diagram for your month year/model. Back in the late 80's I put a 12.5 aux tank in my 72FJ40. The tank was from a Datsun B210. I had to buy a bunch of 2% low ohm resistors in order to get the stock Toyota gauge to read on the Datsun sender. So the back tank would read on my dash meter by flipping a switch. 1/2 was full and E was empty for that back tank. Personally I never really used the meter - when Elsie would "bark" I just reach down and moved the selector to the front main tank

 

[Imfafu]

Alright, so working through the wiring, comparing wiring diagrams, and many hours with the voltmeter… I think my fuel sender relay is primary culprit at this point. Part number 83360-20011. I’m assuming I should have some sort of voltage post relay with ignition on. I have 12v before the relay, zero after. I have discovered the 40 guys don’t utilize this part, but the late 70s early 80s Toyota Coasters do (sweet camper vans .) Does anyone have a stateside source or even a substitute for this little bugger? (Same picture as before but blue circle is the relay)
Thanks for the coming knowledge!

 

[65swb45]

Try the 55 forum or the classifieds.

 

[1969FJ]

Can you open it up and see what is going on ?

 

[45Dougal]

Is that a relay? I thought it was a voltage regulator?

 

[Imfafu]

It is listed as a relay… I opened it up and it appears the ground is coiled around the positive “arm” and the “arm” can open to remove the connection through the relay. Everything looked pretty clean, wire appears intact, I did go ahead buff the contacts. I did not put power to it yet while I could watch, that is my next plan…

 

[45Dougal]

Have you tested resistance across the meter itself?
I think the manual tells you what normal resistance should be

 

[Imfafu]

Update…
I got tired of messing with this for now, just wanted to drive. Put everything back to together… threw in some LED bulbs to make those blinkers and high beam indicators a little easier to see, and now the fuel gauge works! So somewhere cleaning, pushing, twisting something made the contact I was missing. I have to think it may have been inside the relay because I had gone through this cleaning and checking connections process several times with no success before opening the relay. So thanks @1969FJ for suggesting I open it!