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Ghetto Gauge Fix

3148 Views 10 Replies 4 Participants Last post by  John Strenk
After following the recommendation of sanmiam, I realized that instead of trying to educate the principles of gauge operation it might be simpler just to do a quick fix instead of trying to run down many problems that could effect the gauge.

Running an external regulator isn't a new idea, jeeps have run an external regulator decades before the introduction of the AMC era CJ's.

The regulator sanmian recommended was a nice little waterproof design with mounting tabs and efficient 12 volt to 5 volt buck boost circuit. (Don't worry about how it works.) Other regulators require a heat sink to dissipate the heat from reducing voltage. This doesn't need one.

I purchased one from Amazon for $8.59 with free shipping if you have prime.

I put a 12-10AWG Bullet connector on the RED power in lead to easily plug it into the RED power lead in the jeep harness.

Electrical wiring Gas Coil Motor vehicle Auto part

Light Yellow Electrical wiring Gas Electrical supply

You cab cut the black wire next to the RED wire as it's the same ground on the output side and I think it makes for a neater installation

I connected the Yellow wire onto the "A" terminal and the BLACK wire onto the ground point on the speedo housing. It really can be grounded anywhere as the speedometer no longer needs to have a good ground. (Except for the speedo illumination and turn signal and High beam lights. OK so ground it. )

Automotive lighting Gas Electronic engineering Diagonal pliers Auto part

I used one of the screws that attach the speedometer to the housing to mount the regulator

Circuit component Electronic engineering Electrical wiring Auto part Electronic device

And that is all there is to do to hook it up.

NOTE: This doesn't fix everything. You still could have shorted wiring, bad sensors or broken wires in the gauge.
A simple test by disconnecting the sensor wire and testing with an Ohmmeter between the "S" terminal and "A" Terminal and if you get a reading around 20 ohms (+/- 5 ohms) this ghetto fix should work.

Onto the testing.

I hooked my test box up to the gauges and tested the Low band, half band and full position with the regulator and the OEM regulator.

Low Band:

5 Volt Regulator:
Vehicle Car Gauge Motor vehicle Automotive design

Watch Light Gauge Vehicle Car

Half Band:

5 Volt Regulator:
Watch Land vehicle Vehicle Speedometer Gauge

Vehicle Motor vehicle Gauge Car Automotive design

Full Band:

5 Volt regulator
Speedometer Light Gauge Trip computer Odometer

Land vehicle Vehicle Gauge Motor vehicle Car

Any small differences can be corrected with calibration if the gauges are OEM or Crown. Omix gauges are not adjustable.

Pro's ;
Easy to hook up
Not much adjustment to read correctly if any.
Fast fix
No additions needed to the existing harness
No heat or exposed connections to short out.

Slower response time
Environmental conditions could effect accuracy. OEM automatically adjust for extreme temp ranges.

A 'Tip of the hat" to sanmiam for finding this regulator.
Let's give it a name.

Will post temperature extremes tests.
1 - 11 of 11 Posts

· Super Moderator
24,616 Posts
Discussion Starter · #5 ·
Hey John, R your gauges (fuel and Temp) in backwards? My gauges (1980 CJ5) the Empty of cold r on the bottom, and the full and high temp is on top or am I missing something.
You're not seeing things.

These are Crown gauges.
They are backwards from stock.


· Registered
4 Posts
John Strenk, forgive me for sounding stupid, but what is your 'test box'? I imagine some sort of device that will give you the resistance to simulate empty, half full and full for the fuel, or cool, warm, hot for the temp. Thanks!

· Super Moderator
24,616 Posts
Discussion Starter · #9 ·
My test box was home built with certain high wattage resistors that can take a big load for a long time.

Gauge Audio equipment Gas Measuring instrument Luggage and bags

But the ones on Amazon can probably be used but don't leave them on for a long time. A couple on minutes probably would be fine.

This one has 1 watt resistors in it down in the range you will be using it. .

It might be cheaper just to buy the individual resistors.

· Registered
317 Posts
My test box was home built
Those dials look eerily similar to those used on model train transformers - specifically some of the HO gauged ones I have around. My curiosity has the best of me now - any possibility I am merited in the comparison?
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