link to cluster gauge testing

[hemi68charger]

Hey gang.. Is there a nice little setup someone has made to test the gauges on Charger clusters? I have plenty of clusters. I mean, the three act on resistivity, no? So, if that's the case, then there's got to be a way of hooking up an ohm's meter with a dial and seeing if the gauges respond accordingly.......

Thanks,
Troy

[Nacho-RT74]

as far I know there is a way to test and is aplying exactly 5 volts to gauges studs and check for perfect FULL READ on scale

[Plumcrazy]

Chrysler made a tool for checking gauge calibration. It's basically a can with two wire leads attached to it with a three position rotary switch that selects one of three resistance values.  You could also make up some jumper wires using the proper resistors

The LOW position is 73 ohms
The MIDDLE position is 23 ohms
The HIGH position is 10 ohms

Temperature gauge 
The L position should read 120* on the dial
The M position should read 170*~180* on the dial.
The H position should read 250* on the dial.

Oil gauge
The L position should read 0 psi on the dial.
The M position should read about 30 psi on the dial
The H position should read 80 psi on the dial

Fuel gauge 
The L position should read empty on the dial
The M position should read just under 1/2 on the dial
The H position should read full on the dial

All the above are plus or minus about 1/16ths of an inch.

Here's how you can check to see if the voltage limiter is working.

Voltage limiters can be tested out of the car with a few jumper wires and a test light.
Hold the limiter with the terminals facing you.
The horizontal terminal should be on the top. The vertical terminal in the middle and the angled one on the bottom

Ground the horizontal terminal. Supply 12v to the vertical terminal.
Touch a 12v test light to the angled terminal. You should get a pulsating light on the test light.
If the light doesn't flash or stays on all the time the limiter is bad.

The limiter does not provide 5v. It provides a pulsating 12v that averages out to 5v.

[Nacho-RT74]

THAT IS a good test info...thanks about that. 

[Judhudson]

Bookmarked, thanks for the great info!

[hemi68charger]

Plumcrazy:
Great information.... Do you have a schematic or drawing on a working tool? Where did you get your hradware? Radio Shack?... Are there instruments out there that can produce a specified Ohm's value? Also, should a voltage limiter be incorporated in the circuit?

Thanks,
Troy

[Plumcrazy]

Plumcrazy:
Great information.... Do you have a schematic or drawing on a working tool? Where did you get your hardware? Radio Shack?... Are there instruments out there that can produce a specified Ohm's value? Also, should a voltage limiter be incorporated in the circuit?

Thanks,
Troy

A voltage limiter needs to be plugged into the circuit board.   Attach a 12v power source to the circuit board pin that supplies power to the board.  Ground the cluster housing.

Go to Radio Shack and buy these resistors.
271-1101  10 ohm
271-1103  23 ohm
271-1109  150 ohm

Just attach a short piece of wire with a small alligator clip on each end to a single 10 ohm and 23 ohm resistor
Take two 150 ohm resistors and put them side by side and then attach the wires with clips.

The jumper wires are so cheap you could make three of each and have all your gauges testing at the same time.

[xghobo]

Does anyone have pics and a how to to bench test gauge clusters. I have 3 of them on my work bench now and i would like to build 1 and restore it for installation on my 69. Its amazing i know basic electronics but i feel like i need a gauge tester for dummies!

[Silver R/T]

this should be in FAQ

[Silver R/T]

http://board.moparts.org/ubbthreads/showflat.php?Cat=0&Number=1553691&an=0&page=0#Post1553691

[hemi68charger]

I just won a decade resistor box from the egag.. What I'll probably do and see if it works is use my battery charger at the 12v/2amp setting, connect a voltage limiter to it to duplicate the dash to some degree and then tie in the gauge and resistor box... Using the ohm-2-gauge position relationship, I should be able to test my gauges to see if they work.....  Here's a pic of what I won and will use.......

Troy

[dkn1997]

 I have a couple of clusters kicking around in my garage that I am redoing. one's on ebay right now and I have 2 more I want to go through.  I figured if I was taking some one's money for it, I might as well do as good a job as I can. 

I went to radioshack and bought the suggested resistors.  they have a 22ohm one, which is close enough to 23 for me. also bought a 10 ohm and 47 ohm, which I combine with a 22 to get 69.  not quite 73, but I adjust the value of whatever gauge I am testing by a small amount to make up for the difference in resistance.   I just add a tad to whatever the reading on the gauge is supposed to be based on how many ohms I am short of the formula.   I worked it out with a calculator and being that obviousely, the more ohms/resistance you put in the ground circuit, the lower the reading on the gauge.  that's why when you ground them with no resistance, they peg.

instead of worrying about supply voltage, I just use an extra dash plug I have with an extra board with the stock limiter plugged in.  I just run 2 wires from an extra car batt I have laying around.  or a battery charger would work too. 

has anyone else actually calibrated the gauges yet?  I just did a few and it's pretty cool.  looks like one wheel does the lower 1/2 of the gauge sweep, the other does the highest 1/2.  I have about 6 extra gauges and they all were pretty close, I just tweeked them a bit so they will be as accurate as possible.  interesting, I had one oil press gauge that would peg when grounded, but with the 22 ohm resistor, it should have had about 31.5-32 psi, it was 0.  I adjusted it and it's all good now. If it was not for this thread, I would have not known it needed it and when it got hooked up in the real world, someone would have thought I dicked them.  so it's all good..

[mikepmcs]

I gotta ask.  How the heck do you adjust/tweek the gauges.  I know I can't be the only one wondering this.

v/r
Mike

[dkn1997]

on the back of the gauge, there are two open holes.  if you look close in each one, you can see a wheel.  with a small flat blade, you can turn the wheel.  What I have found is that one wheel does the lower sweep of the gauge, the other wheel does the upper sweep.  From reading troy's threads, I figured if chrysler made a decade resistor box for this, then there had to be a way to adjust them, why else make a box to check them, right? 

[Back N Black]

dkn1997 do you have a photo of you set up , i'm not sure whats being powered up,the cluster itself or the homemade three position switch?
Thanks in advance

[dkn1997]

it's troy that's using the box to power up his gauges. 

I just use whatever cluster I am working on.

-make sure cluster has circuit board and factory volt limiter.  Noise supressor not really that improtant, I have done it both ways and haven't noticed the differnce

-I use an extra plug to connect to the large pins on the back of the circuit board. (this is the plug that normally woudl be in your car, the female one)  If you don't have an extra plug, you can use alligator clips to supply 12v to the positive pin.  search this site, there is a diagram on what pins do what.

-run pos wire from a spare battery or battery charger or jumper pack to pos on your board.

-run neg from the above source to cluster frame (I brush a spot w/wire brush for good contact)

-ground appropriate pins for different gauges with a jumper wire to the volt source or the cluster frame.  just grounding will only tell youif they work.  If you want to check the accuracy, see above, get those resistors from radio shack.  run a jumper from one end of the resistor to ground, run another jumper from gauge to other side of resistor, compare to table above, calibrate by moving the wheels to get correct gauge readings based on ohms of resistance.

radio shack sells a pack of 8 perfect sized jumpers for about 5 bucks.  just spend the money and you will have a nice set of jumpers that you can use forever. 

if you are lacking the extra plug for the back of the cluster, you can run the ground direct from the back stud on whatever gauge you want to test.  when looking at the gauges from the back, the neg always goes to the stud on the right.  the stud on the left supplies 5v from the limiter.  NEVER TEST WITHOUT THE LIMITER UNLESS YOU HAVE AN ACCURATE 5V SUPPLY, run 12v direct to the gauge and it could get interesting.

[Back N Black]

Thanks dlkn1997, that exactly what i wanted to know.

[Silver R/T]

I put 9V to fuel gauge to test it. Needle slowly went up, I guess its working. Could I use same test for oil pressure/ temperature gauges? I know Alternator gauge is working. Thanks

[Plumcrazy]

I put 9V to fuel gauge to test it. Needle slowly went up, I guess its working. Could I use same test for oil pressure/ temperature gauges? I know Alternator gauge is working. Thanks

The oil pressure and temperature gauges are tested the same way.