This is a PM which i sent Damon this morning.. i figured i'd post it up here for everyone else's benefit.
The wiring is from a 94 electrical manual, if you have a different year, the colors should be roughly the same, and the position on the plugs should be roughly the same, but you cant quote me directly on other years. 94-96 should be exactly the same, 92-93 should be very close if not exact. The rest is up to you to figure out, but should be close in Gen 4 too.
I suggest you take the gauge cluster out and tap into the power, ground, and lighting wires from there.
The plugs for the combination meter are A-blue 13 pin, B-White 16 Pin, and C-Gray 10 Pin.
Power from 10A Gauge Fuse - B6, Red-Blue
Ground - A6, Brown
Triggered Illumination From 15A Tail Fuse - B16, Green
If you want to make it so the Gauge lighting dims with the stock interior light dimming control knob, ground the gauge LIGHTS only to:
Ground for Meter Illumination - A13, Black
The oil pressure sensor should have 1 wire which goes to the gauge. Not sure what you mean by "and volts just wires to the ignition somehow..."
Yes for the pressure you put it where the stock oil pressure switch is. If you arent going turbo, you dont T it.. just replace the stock one with the gauge one. BUT...
you need a converter from 1/8" BSPT (british standard pipe thread) to 1/8" NPT which is the standard we use here in north america. It is different because the thread pitch is different. 1/8 BSPT i believe is 32 threads per inch or something, and 1/8 NPT is 27.
The part you need for this conversion is Autometer part #
ATM-2269. you can get it from summitracing.com for less than 15 bucks. Also, other dealers carry similar products to this that arent sold by autometer. those are fine too.
If you are going to turbo, then you need this converter and a
standard 1/8 NPT female Tee. One side goes to the pressure sensor, and one side goes to the oil feed on the turbo. You can get the Tee from home depot in brass, or summit in other finishes from various manufacturers. one sample is russell's RUS-661711 at summitracing.com. Now to convert this Tee's female fitting to the female fitting on the BSPT-NPT adapter, you need a
1/8" male to male fitting. this is found at home depot or any other hardware store.
The whole setup should look like this...

Here is a pic of the whole oil feed system on a 5sfe turbo setup. of course this manifold and downpipe is custom made by me, and the turbo is a garrett GT32. This setup will be on the 3sgte, but its still on the 5sfe right now.
I am not sure about the oil temp sensor... I dont know what kind of fitting is on it. If you know what kind of fitting you have on yours, let me know and ill help you out with that as well. If it is some sort of NPT fitting, it can be converted with reducers and other plumbing from home depot and worked into that same T system as the oil pressure.