Gauge Cluster Refresh or What I learned by stuff being broken...

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GoldSwinger71

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When I got my car the seller told me "Oh, the gas gauge doesn't work, here's a couple bucks for the fuel sender."

Getting the steering column dropped was a bit of a chore. I ended up breaking one of the plastic column isolators. 48 year old plastic isn't very pliable. Added some parts to the shopping cart...

After finally getting the cluster out, testing confirmed that the temp AND fuel gauge were both inoperative. I searched the forums and found my answer! First things first, I crossed my fingers that my gauges hadn't taken an extended dose of 12v power. I picked up an RTE voltage regulator, and tested by grounding out the signal post... AHA! The needles move! I thought I was done, and ready to button things up.

The next day, I got a set of resistors to test the ranges of the gauges, and see if they were still reasonably accurate... and the needles didn't budge??? Multi-meter said I had voltage from the regulator, so it wasn't that...

If you haven't had your cluster out, you'll find that the posts for the gauges use little speed nuts which provides the connection to the circuit board. These. Things. Suck. The surface area that actually touches the circuit board is a sliver of metal. A quick trip to the hardware store and I sourced appropriate nuts and washers. Snugging them down, I hooked up some resistors and BINGO!

I also did a swap of illumination bulbs to green LEDs. (SiriusLED 194 bulbs on Amazon) I tested with a variable voltage power supply and found that they dimmed well down to 8 volts... Awesome! I ended up replacing most of the Instrument Bulb Sockets because of broken clips.

Helpful hint, if you get them from NAPA (Echlin Part Number ECH LS6501,) MAKE SURE TO CHECK THE CONTENTS OF THE BOXES. 3 out of 5 of my first batch were the wrong size (1/2" instead of 3/8")

I kept the Oil Pressure light as an incandescent bulb (since it's not an "on/off" indicator,) as well as the high beam indicator.

One final test of every bulb and pin, and we're looking good to go. Tomorrow I'm replacing the headlight switch (the dimmer is a bit crunchy...) and the gauge cluster is going back in. I'll get some pics of the completed install with the LEDs. The blue filter on the cluster goes well with the Green color.

Here's hoping that the fuel tank sender is reasonably in range, and the temp sensor is working too. The temp gauge reads a bit low at the calibrated values, but it's better than reading "0." One step at a time, I guess! If I keep up this pace, I'll have all my immediate projects done before spring hits.
 
Yep! When I restored my ralley dash and converted to the transistor IVR all worked great on the bench and on the test run after it was all installed. Then the next time I went for a drive no gauges at all. I ended up replacing all of those speed nuts with regular nuts and washers and bingo, all the gauges worked again.
 
While your at it you should add a relay kit to your headlights. Your switch will last longer and headlights will be much brighter. I bought this one but there are much better quality ones out there.
https://www.ebay.com/itm/H4-Headlight-Headlamp-Ceramic-Relay-Wiring-Harness-Kit-Light-Bulb-Fix-Dim-Light/201999671717?ssPageName=STRK:MEBIDX:IT&_trksid=p2060353.m2749.l2649

I’m actually using the TruckLite LED headlights so the draw is significantly less.

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Oh and I forgot to mention, I'm adding a grounding pigtail to the screw that used to have the radio suppressor. I'm making it reasonably long so it won't have to be disconnected first before removing the cluster if I (heaven forbid) have to bring it out again.
 
Oh and I forgot to mention, I'm adding a grounding pigtail to the screw that used to have the radio suppressor. I'm making it reasonably long so it won't have to be disconnected first before removing the cluster if I (heaven forbid) have to bring it out again.
I always added a male/female spade terminal disconnect about 4 inches from the inst' panel so my ground wire would unplug like everything else ( except amp gauge of course ). With a little extra effort you could end it behind the left kick panel mirroring how the heater case is grounded behind right kick panel.

Popular belief is using the speedy nuts was to save a coin. That isn't correct.
Those studs are swedged into a fiber board that gets even more brittle with age.
The engineering stand point and practice is, a weak stud gets a weak nut. It's contact at a single thread might seem inadequate but it did work.
Those studs weren't plated and would rust. Some so bad that the speedy nut wouldn't back off. The speedy nut is easily cut off. I had to do that once or twice. To cut off a standard hex nut wouldn't be so easy. In a couple cases the owner had already cracked the fiber board before throwing in his towel and shipping his mess to me.
The amp gauge got standard hex nuts and toothed washers and sure they cost more but... There is no fiber board on that gauge or circuit board contact. There is heavy ring terminals and wires hanging from those more rigid anchored studs plus much more contact required.
The rest of the story... The producer of those studs for thermal gauges knew it would get a pizz poor nut so their quality control could be lax. I found a few of these studs that a standard 10-32 hex nut would not go on.
To run a 10-32 die over one of those studs, knowing how easily the board would crack, was tedious/nerve racking. Yep, did that many times too. Of course most of my practice was focused on those gauges that have 3 studs and 50 years old. What you have is newer and a bit different.
There came a time when my reusable stock was depleted, so I produced a half dozen of the early type boards by hand from F4 fiberglass and re swedged donor studs into them. I think I paid 30 to get the swedge tool made ( R.I.P. Bill ). I quit the gauge service before using all of those boards.
 
Good to go!!! The only problem I ran into was they hot glued the center cap of the Tuff wheel to the hub?!? I was going to try and install the horn switch into the wheel and get rid of that dumb horn button.

Also the glove box liner was completely the wrong part. It sort of looked like the right one but it was way too wide a taper. Anyone know where I can get a correct one? (Ordered this one from Dante’s)

Oh well, another project for another day.

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Looks good. My cardboard glove box fell apart. I grabbed a plastic version from a 70's abody from the pick and pull and it fit good.So long ago I forget what year. Maybe 74?
 
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