Fuel Gauge regulator question

[crj1968]

Hi I am troubleshooting my faulty fuel gauge.
First I found a broken connection behind the kick panel. Thought I had it but no, still a no go.

Right now I have the instrument panel out of the car for testing.

I actually have two of them and both are showing the same behavior.

I have 12V going to the post that powers the fuel/temp gauge and oil and E-brake lights.
I have the case grounded also. I can test it by providing ground to the e-brake light and it works fine.

When I test the output of the regulator (going to the fuel and temp gauges) I get a pulsing on my meter. Nothing that I can really read. Should I be able to read a voltage there? I have read in other threads I should 3-5 volts (?)

Not sure if that regulator thing is bad or not. I also ran a ground wire to the other side of the gauge which should make the gauge go to full, but it still does not move.

Thoughts? Thanks!

 

[BillGrissom]

This has been answered a million gazillion times. It should be a pulsing that time-averages to ~5 V, but would need an old voltmeter with a slow needle to read that. Your Vreg could be inside your fuel gage, depending on the model and year that you didn't tell us, up to ~1973 if you have a factory tachometer. When tired of that clumsy old technology, search "voltage limiter" on ebay for a simple solution. Yes, when you ground the fuel sender input pin, the dash gage should go past "F". With 10 ohm it should be right at "F". Reading "E" correctly is more important (70 ohm), unless you enjoy long walks or meeting strangers who enjoy picking up hitchhikers.

 

[crj1968]

Yeah I know I read a million gazillion posts on it also.

It's a 72.

Was confused about the pulsing voltage thing... Must be the gauge itself....I sawpped in a known good regulator from another car and still same issue- the grounding thing still doesnt work. So I just swapped in the whole cluster from my other (project) car...and it's working now.

Will check out your ebay advice- thanks!