Gas gauge adjustment

[Raywilson]

81 F150 Ranger
I recently installed a new dash gauge setup w a tach n tip meter, which the other set of gauges didn't have.
 Having a trip meter is so awesome!  My old gauge orange needles are really faded, new ones are bright orange.  Well, the new gas gauge reads full up to 125mi into a tank of gas before it moves, the old gauge reads pretty accurately for both tanks.  So I put the old gauge into the new cluster and it looks bad because of the fading.  Is it possible to swap needles between the 2 gauges?  I'm so ham fisted, I'm afraid I'd do my usual and make both inoperable.  I saw a video where the guy adjusts the needle through the hole on the back side.  Is that doable?  You can see the adjustment teeth in one of the holes...
Ray

[viven44]

I used this paint a few days ago to paint the faded needles on a gauge and it worked wonderfully!

https://www.michaels.com/product/testors-fluorescent-enamel-paint-10226505?cm_mmc=PLASearch-_-google-_-MICH_Shopping_US_N_Craft+%26+Hobbies_N_PMAX_LocalOnly_N-_-&Kenshoo_ida=&kpid=go_cmp-18514199957_adg-_ad-__dev-c_ext-_prd-10226505&gad_source=1&gclid=CjwKCAiAopuvBhBCEiwAm8jaMQ6WxlI_h7UsqZUdFwF2xdVSSsgDdfNja6gSjIkneOlnOXFlJqy7IhoC7DYQAvD_BwE

[Raywilson]

That might be the simplest solution. Does it match the original or did you paint all the needles? I've got the LED  bulbs too. They really look good!

[viven44]

Thanks! Yeah I painted all of them and the color is a close match if not spot on. If you go this route, make sure the little bottle is shaken and stirred well. And use very little on the tiny brush. It goes a long way. You don't want to drip the paint on the gauge for sure. I did 2 coats. And make sure its fluorescent paint.

[viven44]

On the LED bulbs, they have polarity so you have to install them in the correct direction. Else they won't work.

[Raywilson]

I found that out.  Annoying to have to pull the dash out again to reorient the bulbs but they look so good. Don't dim very well

[viven44]

I have been there as well and pulled the cluster again to fix them. What I do now is use a spare battery, with a resistor and inline fuse in series (just extra protection) with the led bulbs to mark out the positive and negative terminals so I know which way to install.

[mat in tn]

I find them never bright enough. I have not wanted to dim them

[ArdWrknTrk]

Not all of them are polarity sensitive, and many of them DO dim💡
We like hi-po parts for both the needle paint and the LEDs...

Vendor ratings and reviews in the marketplace section....

They also have all the shop manuals available on CD, if you want a physical copy

[viven44]

I just assumed they were all polarity sensitive, as they are a transistor fundamentally. Looks like I need to go back to school

Is it this one ?

https://www.hipoparts.com/fluorescent-speedo-gauge-needle-restoration-paint/

[ArdWrknTrk]

Diodes are -of course, by definition - polarized.
Some bulbs have a rectifier bridge built in....

[Raywilson]

So, fluorescent red or orange?  That's a great site! Paint is the way to go...

[BigBrother-84]

Raywilson wrote

So, fluorescent red or orange?  That's a great site! Paint is the way to go...

Last year, I changed all the instruments gauges for NOS units.
Well, almost all of them, since the only one I was unable to find NOS was the tach.
So, I had to paint its washed out pale needle to match the «new» original color.
I had on hand a Rustoleum Marking orange spray paint.
I tested it on another old unit (with a thin paint brush) and it matched perfectly.

[viven44]

At that price I would buy both and see which is better. Also try the combination of both mixed maybe ?

[Raywilson]

The reviewers at Hipo Parts said they used the red, so that's what I did. Thanks for all your comments and advise! This is a great site!
Ray

[viven44]

I had guessed they had some sophistication to sense polarity and work, just not the LEDs by itself. Looks like they are SMD (surface mount LEDs) so the SMD package has the ability to surface mount other components along with the LEDs. Pretty cool.

At $9 a pop though they are on the expensive side. An entire dash would be approaching $100. Not sure I have the stomach for that knowing I can test the polarity and install them myself.

This below here is what I think I would go for
https://www.hipoparts.com/ultra-bright-1-smd-3-led-bulb-194-t-10-wedge-super-wide-angle/

[viven44]

Did you spray directly on the needle or use a brush to apply ? The Tach is a pretty stout gauge so I assume you masked all the areas of the gauge except the needle ?

When I'm painting the needles, I'm always afraid I'm going to break one of them as they are so feeble

[ArdWrknTrk]

That's marking paint.
It isn't meant to fluoresce

[ArdWrknTrk]

The Sylvania Evo (Ego?) bulbs are pretty good as far as no polarized and ability to dim.

I have some of them too.

[viven44]

Couple of colors called "Fluorescent Orange" or "Fluorescent Red-Orange". Marketing gimmick or real ?