Gauge Cluster Voltages

[knighthawkgamer]

I am thinking about making a custom gauge cluster and I was curious if anyone would happen to know the voltage ranges on the different gauges. I am guessing the max would be 24v. Once I get mine I could connect a meter and check the voltages coming off each gauge but I wonder if anyone already has this information available.

 

[papakb]

Some of these gauges read current and not voltage so be careful.

 

[knighthawkgamer]

Some of these gauges read current and not voltage so be careful.

Good to know, I figured if I can't find the answer here I would resort to checking voltage and current.

 

[TOBASH]

28Volts... That's what the alternator puts out my friend. We say 24 because the batteries are about 12-13Volts apiece, but the try range goes up to 28.

Amperages need to be checked BUT 28V is HMMWV standard for gauges, even if you have a dual voltage rig.

 

[knighthawkgamer]

Just to confirm, we are talking 28V but the gauges show different values based on the amps making it to them.

 

[TOBASH]

Yes, 28V!

24V cars use 28V.

12V cars use 13-14V

 

[Coug]

24V nominal. just like civi vehicles are mostly 12V nominal.

 

[knighthawkgamer]

Thanks all, anyone know the amp ranges? I know this is specialized information but I am trying to prep schematics and parts.

 

[Coug]

none of these should be very high amperage. My understanding of gauges and senders is voltage flows through the sender, and the gauge just measures how much voltage drop there is due to resistance, and shows it as an easy to identify value.
I could be wrong, but last time I looked at mine the wires were all pretty tiny.

 

[Retiredwarhorses]

All the gauges have one thing in common.

1. one wire is 24v switched
2. each gauge has a ground
3. each gauge has a source signal from the component it’s reading. So I’m not sure where these Amps come into play,

 

[Milcommoguy]

Not Amps... Milliamps. And I don't have the dope your looking for.

Gauges work with small current variations, producing a magnetic field, indicating zero to full scale.

Resistance values of senders in ohms typically 0 to 60 and could go as high to 500 with some designs.

There are two types of electrical gauges in the Humv. Moving coil (voltmeter) and the double coil (oil, temp, pressure).

Here's a print to show connections to the double coil.



Gauges and senders are purpose matched to work together as to track small resistance values indicating calibrated oil, temp, pressure readouts.

The Voltmeter is sensitive to change (as required) and is a characteristics of moving coil designs.

Double coil meter / gauge advantage are insensitive to voltage variations by design, providing accurate readings over a fluctuating supply voltages as in a HumV.

Could be a bit of experimenting to "dial in" your results.

How about a military universal "glass panel" cluster with configurable layout, speedo and tach, any gauge you could ever think of, all at the same time, blue tooth enabled, plug and play ???



The MO U know to GO, CAMO

 

[papakb]

"each gauge has a source signal from the component it’s reading. "

The way the gauge "reads" the sensor is by displaying the amount of current flowing thru it. As the pressure or temperature changes the resistance of the sensor changes proportionally. This is accordance to Ohms Law or I = E/R where I is the current in amps, E is the circuit potential in Volts and R is the resistance in Ohms. Typically E (volts) in a HMMWV is a fixed 24 volts so you can see that the current (amps) will change with any change in resistance. That change results in the current flowing thru it to vary and that varying current causes the needle on the gauge to vary with it.

The only gauge that's different is the voltmeter and as Cam says it's a simple moving coil design where the needle simply moves as the voltage changes.

 

[TOBASH]

papakb, many gauges work by looking at the Voltage. A variable resistor (rheostat) upstream will affect voltage, and the gauge will read that.

Best!

T