I realize that the cold weather will slow down the tach, I've seen the "ghosting" that you're referring to, however I'm still getting a significant amount of tachometer "lag" even when it's hot out and the car has been warm for a long period of time...


It seems to me like something is interfering with the tachometer signal or that something is wrong with the tach... If the alarm system were somehow drawing a significant amount of current from the tachometer signal wire, could this be throwing off the readings? I struggle to understand how something could cause the electronics to be slow to respond... Or perhaps if the instrument cluster were not getting sufficient current due to the alarm drawing current from a bad location, could this cause it to slow down?


Another thought: Could the tach signal be going through the alarm system first, and then to the tach? If this were happening I suppose the lag could be due to the alarm system... Does anyone know of alarm systems like that?

 

well, perhaps it's time to finally get one of these beautiful stack tachometers... bit pricy, but I just love watching that needle sweep...

http://thmotorsports.com/stack/stack...r/g-62124.aspx

 

If the alarm is ran off the same wiring then that absolutely could be the problem. Otherwise, you're just seeing things, LOL jus kidding haha

 

lol! That's what I'm afraid of... damn hopefully the alarm isn't spliced inline in such a way that I'd have to replace the respective wiring harnesses...

 

i think the only other reason this could be happening (that isn't actually electrical in nature), that has not been mentioned yet, is a clutch that is going bad can make a similar situation happen.