What does the voltage limiter control?

[Super Blue 72]

Hi guys, just a goofy question I wanted to throw out to you guys.  Thanks in advance! 

On my car ('72 Challenger, Rallye gauge cluster), the fuel sending unit wire has no voltage to it (checking from the tank and grounding) and the temperature gauge doesn't work and has a new sender.  I didn't check yet if there's voltage to the gauge or not.  The oil pressure gauge DOES work.

Question is:  Does the voltage limiter (Is that what it's called that provides voltage to the gauges?  From 12v to 5v?) provide voltage to all 3 gauges or just the temp and fuel gauge? 

Thanks a bunch! 

[71 DEPUTY]

provides 5 volts to all three of the gauges- only difference is if you have a low fuel option- then the low fuel relay provides it's own power.

idiot lights use 12 volts to run!!!

[Super Blue 72]

Cool!  Thanks for the reply! 

I'll have to check out the fuel and temp gauge situation in more detail.   

[ted]

THE  wire to the fuel sending unit is the ground for the gauge, has no power.

[Super Blue 72]

THE  wire to the fuel sending unit is the ground for the gauge, has no power.

   Doesn't the 5v reference voltage travel through that wire and the fuel tank sending unit vary the resitance? 

So if I check for voltage on that wire it should be 0v, not like 5v or something?  Thanks!

[71 DEPUTY]

check one side of the limiter- should be 12 volts
check case of it- should be grounded
the other should be pulsing- it averages out to be about 5 volts.

*** note- if the dash is out of the metal dash frame- you will have to ground the dash to the frame as the voltage reg. will not work. It's a good idea to add a ground this way as the voltage reg, all the bulbs, tach, dome light switch and the wiper switch needs a ground to work!!!!

John Mac

[Super Blue 72]

Cool, thanks John! 

Something to play with once the sleet stops!