Autometer Cobalt C2 gauge problem

[ZombieSoldier]

I posted this up in the 7.3 section but trying to find some definitive answers... anyone?

I have autometer Cobalt C2 electric gauges on my 1999 F250. I have 0-30PSI boost, EGT, and Trans Temp. all gauges shine the same bright blue level. My boost works great moves like it should and my truck maxes out at 24PSI. Trans temp again moves the way it should, no issue. EGT... well that's a different story. for the first 2 months worked as it should, but recently it just spikes around however it wants to. only time its steady is if i am on the highway at a steady speed for more than 20 minutes then it operates like it should. I dont even know where to start trying to figure out what is wrong. i checked to make sure the probe is in there correctly, and it is... dunno what else to look for. Please help me. next month i have a dyno day to go to, and dont want to risk grenading anything due to a gauge that isn't working properly. Only time i know the EGT's are getting to high is i get a check engine light right at 1300, and i dont like seeing that.

[taskforcefreddy]

I would buy another one and simply swap out the gauge to see if that reacts any differently. If it does, you know you have a faulty gauge and then decide how you want to go about returning it. I've used the cobalt series and they're awesome. I think you can order them through autozone so if that's the case, you can probably return it to an autozone as well (I don't think they have them on their shleves). Like you mentioned, you don't want to damage anything and dropping $80 for a new gauge is a small price to pay for some peace of mind.

I had a weird situation when installing my EGT gauge on my 6.0 as well. I had both an Autometer and a Prosport EGT kit and somehow they got mixed together. I wanted to use the Prosport because of the interface/warning system it has. I ended up plumbing up the Autometer by mistake and I simply spliced everything up to the Prosport and it works just fine. Bottom line, I'm guessing it's the gauge, not the probe that's bad. Good luck.

[ZombieSoldier]

ok guess i will check out the wiring first?? then if thats all good i will try replacing the gauge its self..

[MWilbur516]

Those gauges are notorious for acting like that when the ground is loose.

[ZombieSoldier]

Where is ground most likely bad at? At the harness or the grounding point? Because I traced all the wiring today and found nothing.

[MWilbur516]

Could be either place. Test continuity between the ground at the gauge and a known hard ground.