I recently put an oil pressure guage in my cheap dash with no vents. It's an 86 4x4 300 F-150 4 spd. Anyway I used the hole drill and I fiqured while I had it all apart why not put another custom guage on the other side, so I decided on water temp. Anyway after a few custom fittings later I get the temp. sender installed right off of my water pump going into the heater hose. I took the sender to my garage, unplugged the electrical wire and left it sit. Anyway the next day I'm drivin and for some reason both my guages work, factory and custom, the cus. stays right at 190, my fac. goes up in the normal range and sometimes up to the L although the cus. still says 190. Anyway my fac. oil pressure guage died right away (what little it did), but did I tap into the wrong sender hole? b/c I looked all over the side by the frost plugs and stuff and there are no plugs there. Has this guage just memorized this engine's heat patterns, b/c it follows the cus. pretty close as it warms up in the morning and when I turn the heater on high, they both drop slighty.

Redneck-Cowboy

By the way my fac. oil psi. guage was way off, it said below normal, but the custom says 50 psi. all the time, the trucks got 220K to, all original internally.