I always install a 'T' when putting an oil pressure gauge on a car/truck with the Idiot light to keep both.
My 84 Shelby had one from the factory. I think all Ralley Dash cars from the 1980's did.

Retired, US ARMY 1973-1994
ASE mechanic, Electrical 1994-1997
Retired GTE/VERIZON/FRONTIER 1997-2015


Posting cheap tech help (CRAP) here since Nov 97, 1000's of posts, some may be good.

03 Suzuki Burgman 650(Burger King) Scooter
65 Formula S Cuda
78 Little Red Express Truck
98 Buick Regal (wifes car)