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Discussion Starter #1 (Edited)
My temperature gauge has read low for 30+ years (so has my fuel level gauge). About 5 years ago I installed a new solid state dash constant voltage regulator thinking that was it. It wasn't.

I'm now I'm in the process of a major rebuilt of a bunch of things. Since I had the dash apart, I replaced both the temp and fuel gauges with new ones from CJ. I also got a new temp sender (and a new tank with a new sender - for EFI). I also replaced the engine side harness and cleaned the connectors on the under dash harness.

I just got the dash all back together (whoops) and decided to test the temp gauge (yes - I should have tested it before reassembling it). Reading up on the ohm values for the sender and doing a quick boil test, I found that 10ohms should be the full right end of the scale and the middle should be 25ohms.

I dont know where to turn now. Any thoughts?

See below for some pics and measurements. I only had 10, 22 and 33 ohm resistors.

-Kyle

Boil test:
75 - 265 (ambient)
145 - 78
160 - 58
175 - 44
185 - 37.5
195 - 32.5
200 - 30
205 - 28
210 - 25.1
212 - 24.5


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Your sender isn't TOO far off. What you need to do now is adjust the GAUGE high and low limits. It looks like you have a way to provide a 10 ohm reference to the gauge, so do so and then move the gauge high limit to place the needle right on the thick white block on the "H" side. If you have a way to provide a 75 ohm +/- reference to the gauge, do so and adjust the gauge low limit to place the needle on the thick block on the "C" end of the gauge. Ideally, when you are done....or if you can provide a +/- 25 ohm reference to the gauge the needle should read about dead center.

In the photo below, the adjustment holes in the back of the gauge are shown by the red arrows... you can see the "teeth" of the adjustment "wheels" that you turn, like the star wheel on a brake adjuster.... only twisting, not prying.

760265
 

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Discussion Starter #3
THANKS!! I havent had a gauge apart. How do I adjust those limits?
 

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You can see the inside in the attached pic. TheRktmn says to adjust:
With a 73 ohm resistor for low and a 10 ohm resistor for high and a 5VDC power supply you can set the gauge back to factory specs.
Use a small screwdriver in through that hole to engage the teeth and move the arm. You will see the pointer move.
Once you change one you need to check the other since it will change some too.

Radio Shack is still around on line and sells individual or resistor packs. You have the power supply in the car, you just have to tap into it.
 

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Discussion Starter #6
Awesome! Thanks guys!

Any tips to pulling the gauge cluster more easily? It was pretty easy when I had everything apart (steering column out, etc). But with it all together, I seem to remember it being hard!!

Thanks again!
 

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Any tips to pulling the gauge cluster more easily? It was pretty easy when I had everything apart (steering column out, etc). But with it all together, I seem to remember it being hard!!
It isn't difficult on my year- just lots of stuff connected- some people complain about the speedometer and at least one person with a 68 got to it after removing the heater controls, but I saw no reason to do that on my 69. From the photos your dash looks to be in very good shape. When you reinstall the gauges be very careful not to allow the electrical posts of the gauges to contact the surrounding sheet metal of the panel- that's where most people have trouble.
 
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