Autometer EGT interference issue
 

I installed an autometer EGT in my '94 GT tonight and noticed something odd in the behavior of the gauge. When the motor is on and running, the needle in the gauge points straight down and wiggles all around. BUT, when the ignition is turned forward, but the motor is not cranked, the needle reads the correct exhaust temps. I re-checked the wiring and even changed the grounds, but still did not have any luck. Does anyone have any experience with these gauges or possibly have some knowledge as to what my problem may be. I'm assuming the motor running is causing some sort of interferance, but do not know exactly how and what needs to be done in order to compensate for this. As always, thanks again. I almost forgot, for positive 12V feeds I used wires from the existing stock radio harness.
Matt

Re: Autometer EGT interference issue
 

I may be able to trouble shoot for my problem in another way. Does anyone even have an EGT installed? If so, the route your probe wires take may be different than mine. Autometer mentioned that I may be receiving interference from ignition components, such as the plug wires. Due to the fact that my msd wires continuously wiggled off the plug, I put my stock wires back on for a temporary fix. Would it be possible that the stock wires are emmitting much more electrical noise than per say an aftermarket plug wire would?

Re: Autometer EGT interference issue
 

Are your EGT wires shielded? Mine have a stainless steel overbraiding (shielding) that prevents/minimizes interference from other sources. A poor engine ground could be the cause as well so make sure your engine is adequately grounded.

Re: Autometer EGT interference issue
 

The EGT wires are wrapped quite well. I have been dealing with some engine ground issues for a while now. Where would you recommend adding some grounding wires?