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Installing an electric Oil Pressure gauge


New Member
May 9, 2024
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Fort Wayne, IN
hey all. new here but long time member over on FABO. I have purchased an oil pressure gauge and plan to retrofit it into my 72 A-body

The gauge is an electric type from a late 60 early 70 dodge truck. I've downloaded a wiring schematic and looked at photos of the back side of cluster. I do not see any voltage regulator being used. It appears this gauge is wired to keyed 12v and grounds through the sender. Can anyone confirm?
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Doesn't appear to be using any kind of PCB for this cluster and I'm not seeing any voltage regulator.
Screenshot 2024-05-07 at 1.15.02 PM.png

Here is the Oil Sending Unit I picked up to drive that gauge
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71+ A-body cluster PCB

I would use a nylon hat washer that's sized to the diameter of those bulb holder holes and run the gauge posts through them and hold them in with some speed nuts like the ones on the fuel/temp/ammeter gauge posts.

Jumper from oil send trace to negative post on gauge. Jumper 12v to the positive post.

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I will be installing this gauge on the right above the wiper switch and relocating the brakes indicator

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install one of these for the new brake idiot light wired to ground and original trace feed.

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That looks like the same dash as my A100. I have a voltage regulator mounted behind that 8-way spade distribution tab.

I am fairly sure you need a 5-volt supply to the 'S' terminal on the oil pressure gauge, and the other terminal gets the wire from the sender.
The engine block serves as the ground for the oil gauge to work.

The 5-volt supply will come from the dash regulator - which should be a small metal cased three-pin plug-in module behind where the Ammeter is positioned.