Question on Dash Gauges
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Question on Dash Gauges
Hello All, I have a 1972 F150 pickup. I am having trouble getting all of my Dash Gauges to work. Can someone please tell me HOW these gauges receive Power?
Are they all connected? And HOW are they grounded? Do you have any additional info on these Gauges?
Thank you. John D.
Are they all connected? And HOW are they grounded? Do you have any additional info on these Gauges?
Thank you. John D.
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Joined: Jan 2001
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From: Virginia
You have a common 12v power wire coming in from the cluster plug. Somewhere on the cluster should be a square silver box. This is the gauge power regulator. It turns the 12v dc power to a pulsing power averaging about 5-6v. If you put your meter on it, it will look like a turnsignal flasher.
There is a common ground in the cluster, but the ground that works the gauges is the wire to the sending units. The temp gauge, oil gauge, fuel level gauge are all looking for a varying ground from the sending units. The sending units are just variable resistors. When the temp and oil pressure sending unit screw into the engine, they are using the engine ground for the gauge. Same with the fuel tank, there is usually a separate wire that is grounding the sending unit itself.
If you want to test the gauges, simply power them up through the gauge regulator, and find the wire going to the sending unit. Ground the wire going to the sending unit and the gauge will swing full scale, empty or full. Take the wire off ground and let it hang in the air, the gauge will swing the opposite way full scale.
There is a common ground in the cluster, but the ground that works the gauges is the wire to the sending units. The temp gauge, oil gauge, fuel level gauge are all looking for a varying ground from the sending units. The sending units are just variable resistors. When the temp and oil pressure sending unit screw into the engine, they are using the engine ground for the gauge. Same with the fuel tank, there is usually a separate wire that is grounding the sending unit itself.
If you want to test the gauges, simply power them up through the gauge regulator, and find the wire going to the sending unit. Ground the wire going to the sending unit and the gauge will swing full scale, empty or full. Take the wire off ground and let it hang in the air, the gauge will swing the opposite way full scale.
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