I wired up my Autometer Cobalt EGT gauge but haven't put the probe into the header yet (have to take it to the shop to drill a hole). When I start the car the gauge does its auto-calibration and then stops somewhere between 400 and 500 degrees. If i move the probe around the needle jumps around a bit. Why doesn't it display room temperature (~70 degrees)?

...try grounding the probe to the body of the car---touch the probe housing---NOT THE TIP OF THE PROBE to a bolt under the hood.



.....ya din't take a lighter or anything like that to the probe did ya????...if so, ya mebbe killed the probe