I am not really sure If I should do a build thread or just leave what I did and how I did it in here, but anyways below I will have the wiring, and how I made the dash, what gauges I used and what gauges are compatible with the 1998 Jeep TJ and I would assume other year TJ to a extent.
Part List:
1/4inch plywood
Stuff to make your Fiberglass
Gauges:
https://www.autometer.com/3-3-8-quad-gauge-speedometer-old-tyme-black.html
20 gauge wire for speedo sender
18 gauge wire for the rest
fuse for the power wires for the 2 gauges
switches
Phone Mount:
https://www.amazon.com/dp/B0CCRZ7TS8?tag=wranglerorg-20
Total Cost: about 800$ didn't have to pay for fiber glass because my dad had left over from a earlier project.
Dash:
I started by removing everything, airbag, plastic dash it self, metal frame the dash mounted to, and so on. Then I took a piece of 1/4 inch plywood and started making the flat piece that would go from one end of the jeep to the other, after that it was a matter of making the piece to fit on top so it would meet with the windshield. If anyone wants the measurements and or diagram for the dash just let me know and I can make a template so other people can use it. I do plan to refine it and or make it better so it is a bit easier to use and fit gauges in.
After I made the plywood template I prepped the plywood so I could use it to make a fiberglass version of it. Then after that it was just a matter of cutting whole for your gauges and any switches you would like to mount. By using fiberglass it made drilling very easy.
light Wiring:
First I removed this switch
While doing that I figured out what wires turn my lows and highs on along with my running lights.
Here are the colors:
Running Lights colors below
When connecting the wires I took the green/white wiring and red/white wiring and put them on one end of a switch then I took the green wire in the back and put it on the other end. This gave me my high and low beams.
Next I took the whiteish/black wire and yellow/black wire and put one on one end of a switch and one on the other. This gave me my Running lights.
So white/black to yellow/Black = running
Green/white and red/white to green = low High.
Gauge wire:
Gauges used
https://www.autometer.com/3-3-8-quad-gauge-speedometer-old-tyme-black.html
My gauges included a water sender, fuel sender, oil sender, and speedo sender.
A couple things to note for my jeep at least the fuel sender is a 220-20ohm and these gauges are rated for 240-33, so I haven't done it yet but I will be installing the new fuel sending unit next to my fuel pump in the next couple of days.
Also as stated before in this thread the jeep tj 98 speedo sender is a hall effect sensor that outputs about 65,000 pulses per mile I think, going off of what I could find online. So this means that any speedo gauge that has a range including 65,000 so for example my speedo gauge includes 500 to 400,000 pulses a mile.
With this said I took a 20 gauge wire and spliced it into the existing speedo sender located at the rear of the transfer case shown in the picture below.
The wire color you are gonna wanna tap into should be white with I think a stripe but I don't remember but I know for sure it is white.
This is the water sender I used
This is the oil sender I used
Things I still need to do, wire my fan for heating, make a vent for defrost, but I am waiting to go back to college so I can 3d print some vent lines for free so I don't have to go through a ton of trouble. Once I get it working and so forth I can post the files here for anyone that wants to use them, I can make a 3d model of the dash as well if anyone is interested just let me know.
