Question on Dash Gauges

[hombre292]

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 the Gauges receive Power ? Are the Gauges connected?
And HOW are these Gauges grounded ? And does anyone have any additional information on the Dash Gauges ? Thank you.
John D.

[6166 Junkyard Dog]

one thing first is YOU CANNOT Mix up the gauge panel between a truck that had ALL GAUGES and one with 2 Idiot lights and 2 Gauges since the wiring harness are different between the 2 ,, the 70/72 should have a printed circuit board so unlike separate gauges you can test separate and earlier trucks had some with separate wires to each gauge then to one plug that was separate and later trucks had a plug that plugged into the circuit board

[FarmMotorSports]

There is a 5V regulator on the back of your cluster, a small rectangular metal canister.
This two wire connection feeds 5v to fuel, temp, and oil press gauge. (Most Idiot lights get full 12v feed)
Each gauge is then variable grounded by the sensors on the engine.

NOTE, 12V to the gauge even for a moment will typically blow the fine windings that make them work.
If testing the IVR (5V regulator) you will see it bounce all around 5v with a digital meter...
A needle meter will tend to hover around 5v when things are normal. You can test ground the sensor end and cause movement of the needle.

A search on here or eBay should net you an image of the IVR...
The sensors MUST match the gauge or light they were designed for.
So if you swapped gauges for dummy lights, you must install the proper gauge harness and sensor.

[mongrot]

one thing first is YOU CANNOT Mix up the gauge panel between a truck that had ALL GAUGES and one with 2 Idiot lights and 2 Gauges since the wiring harness are different between the 2 ,, the 70/72 should have a printed circuit board so unlike separate gauges you can test separate and earlier trucks had some with separate wires to each gauge then to one plug that was separate and later trucks had a plug that plugged into the circuit board

I unfortunately found that out the hard way when my truck wouldn't charge at all..

[mongrot]

https://m.imgur.com/t92OAsV
https://m.imgur.com/jCHbcyu

Here's wiring diagrams. Don't know if the pictures work or not though