I have an 89 turbo w/digital dash and my oil temp/psi gauge is a combo analog next to the boost gauge, and wired straight to the sensor. if yours is the same and both dont work i would guess the gauge is bad. or the wires did not get hooked up right after the turbo swap.

 

Dont forget the IC needs to be inlet/outlet on the same side, mount it toward the drivers side, ditch the A/C and get a pathy intake, then get an electric fan. Just run the plumbing through the fender well on the driver side. There some stuff on hybridZ, I think, pretty good stuff.
How's the car run? My car didnt like to run if the oil pressure gauge dosnt read. It was running like crap, the voltage would fluctuate and the oil pressure would drop off, I replaced the oil pressure switch on the motor and all that junk stoped. so if it isnt running weird and trying to die at stop lights, but the gauge dosnt work I would guess it is the gauge.