ok 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.

 

Where is your ground wire for the EGT gauge? Is it chained to the other ground wires for the other gauges?

 

yes it is

 

Move it to a ground closest the battery and by itself... I had this issue with my Autometer ultralites and called Autometer and they said that usually fixes it. I moved it and it's been good for 8 months or so.

 

gotcha. im about to go out and rewire my glow plug wait light so i will do this at the same time.

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im wondering. all i had at the time was speaker wire.. i wonder if that has something to do with it. im about to switch to actual wiring.

 

Get rid of the speaker wire...

Your check engine light has nothing to do with your egt's. The pcm has no idea what egt's are. Also, dont even look at the pyro while on a dyno. You can not hurt your motor on a dyno from egt's and they will be very high anyway.

 

Speaker wire is gone. That was used in the glow plug wait light, but tht is already taken care of. Why woul the check engine come on every time the truck would hit 1300? Every time? Think it could be something Tony Wildman put into the tunes?

 

More then likely its a ICP code that is triggering your SES light. There is no way for the PCM to know what EGT's are... Its the same as asking a 6 month old what EGT's are... Just no way.

The reason it seems to be related to the EGT's is because the only way you can reach 1300* is to ROD on it hard, which normally pegs the HPOP and sets the code.

Nothing Tony can put in the tuning to trigger a SES light based on EGT's because the PCM has no way of knowing what EGT's are.

 

Gotcha. Now back to the gauges. Can you point me in the right direction? I have checked the grounds and all seems well.