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I have a centroid fuel gauge sending unit. The manual tells me I need to power my stock fuel gauge with constant 5 volt power instead of the pulsing 5 volts from the factory. I have an automotive 12v to 5v converter, I'm just not sure what wires to splice into to make it work. I've been unable to find a wiring diagram. Does anybody have any ideas?

Note I have a tach. Thank you! :)
 

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The pulsing 5v to the gauges is generated by the instrument voltage regulator bolted on to the back of the instrument cluster. It looks something like this:
741301

I'm not familiar with the centroid sending unit, but I think you should just be able to wire your new converter in place of the old IVR and then it will provide the constant 5v to all of your gauges.

You can download the wiring diagrams over here.
 

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Discussion Starter #3
The pulsing 5v to the gauges is generated by the instrument voltage regulator bolted on to the back of the instrument cluster. It looks something like this:
View attachment 741301
I'm not familiar with the centroid sending unit, but I think you should just be able to wire your new converter in place of the old IVR and then it will provide the constant 5v to all of your gauges.

You can download the wiring diagrams over here.
Hmm, i'll take another look at the instrument cluster because I don't remember seeing anything that looks like this. I have seen pictures of a 67 and I think I saw something that looks like this 9v battery connector, but I'm not sure about the 69. Thank you for the quick response! Hopefully constant 5v to all the gauges won't mess anything up.
 

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Discussion Starter #5
THank you so much for the information! SO I have this thing laying around: https://www.amazon.com/gp/product/B07P663XJV/ But I would rather not splice into the wiring if not needed. Just before I saw this reply I ordered this: Constant Voltage Regulator 1969-1973 which to me seems like the best of both words if it works. Thank you :)
 

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The CJ pony parts you ordered will have the bimetalic strip generating a pulsed 5v, not what your looking for.
 

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The CJ pony parts you ordered will have the bimetalic strip generating a pulsed 5v, not what your looking for.
That is odd, it says it is constant and no where does it mention being pulsed.
 

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Discussion Starter #11
I think this should work for the link he's trying to post:

Maybe.

That link on CJ's web site says that the one you ordered is solid state not the old bimetallic strip so you're probably ok there. Still it never hurts to know how to make your own.
I am familiar with how to make my own. The fuel sending unit actually comes with directions on how to DIY one with fuses and a radioshack components. I also ordered just a regulat 9 volt battery terminal so if the pony parts one doesn't work Ill try this next. Way better solution than splicing into the wiring...however I actually still have yet to find where this 9v battery terminal is on the instrument cluster...it isn't obvious.
 

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I don't have a 69, but when I looked at the part on CJs site that you linked it listed a recommendation on the bottom of the page for the dash circuit piece. Looking at that for a 69 with a tach I think the voltage regulator plugs into the floppy looking piece just to the left of center in their picture.
741341


I'm sure someone with a 69 will jump in here and correct me if I'm wrong on that.
 

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It is pretty much in the dead center, attached to the back of the console. Part of the printed circuit board lies across it and is plugged in. If the console is in the car and you're reaching around trying to find it. It would be just to the right of the speedometer cable.
 

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Discussion Starter #14
Alright so I installed the CJ voltage converter. Upon simply adjusting the empty and full screws on the sender from min to max I am able to move the girl gauge needle from empty to full. The needle seems to no longer jump around and is consistent when engine running and off in accessory mode. I'm going to remove the probe from the tank and do a full calibration. Sadly I can't take it for a ride nor put a full tank of gas in it as it's going to be a few months before winter is over and I can take it out the garage. Thank you everyone for the help, hopefully I can get this working for summer!
 

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If you find you still need a "constant" 5V source, PM me. I've been there done that and have a schematic. I too run/ran a Centroid Sender 76/6 OHM unit.
 
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