I'm completely stumped with the install of my autometer oil press and oil temp gauges. I installed the EGT gauge without a hitch, even with having to tap into my existing turboxs egt probe for the signal. I cannot seem to get the wiring right with these two gauges. So far I have:

Primer: Each gauge (oil temp and press) have terminals for 1) Gauge Ground 2) Sensor Signal 3) +12v switched power

1.Installed everything once, Oil temp seemed to work at first, but soon pegged to 300 degrees F - sensor seems ok because it gradually warms up but looks like it is reading double. +12v seems to be ok on everything because lights work perfectly.

Oil Pressure pegs at 100 PSI and will not change in any driving condition/state of engine warmth.

2. Took everything out and rewired very carefully
-Realized that the sensors might not be grounded because of teflon tape so I attached ground wires to the sensor bodies.
-All grounds made to factory ground points (gauge grounds and sensor grounds at two different points)
-*autometer instructions call for engine ground near the sensor, but I've gathered that any ground on the engine (or car for that matter) will do because of essentially zero resistance.

So now the gauges just peg even when engine is not running. I tried removing both of the gauge grounds, and after doing this the gauges do not read anything. So it seems that the problem lies in those two grounds, but then again I'm not sure and if I wasn't electronically challenged I probably wouldn't have this problem.

Any help would be greatly appreciated as I'm trying to get this install finished once and for all.

-matt

First of all, don't use teflon tape, because the sensors are designed to ground through their threads. Use something like the following (be sure it's "high temperature"):
http://www.midwayautosupply.com/detailedproductdescription.asp?4353
In order to be sure you have a good ground contact, just apply a thin ring (about 1-2 thread widths wide) starting at about the 3rd thread in from the end.
To test if the engine metal near your sensor is grounded well enough, just unplug the wire from the sensor and touch/attach it to the engine metal. The gauge should read zero. If it doesn't, then there is too much resistance between the nearest grounding point and the sensor -- run a wire from the grounding point to make a new grounding point near your sensor. (But first, to verify, touch the wire to to one of the main ground points and it should now read zero)

Thanks a lot! I thought that the teflon tape might cause a problem, I will try all of this today and post my results, hopefully this will fix it.

-matt

Ok so I tested the gauge by first placing the two ground wires on a factory ground point, and then touching the sensor wires to this same point. However, the gauges still peg at max value as soon as the ground wire is touched to the ground point. Touching the sensor wire to the same point yields no change in the gauge reading. What's going on here?

-matt