Hello everybody, I'm just posting this topic regarding tachometers reading wrong. This goes for 94 3VZE engine. I've always had problems with the tachometer reading wrong but i've learned to let it go. It would always read 500 rpm when i knew it was clearly idling at 800. I thought it might be my alternator not providing enough power due to the whistling it had started to make. I just finished replacing my alternator and now it works correct sometimes and othertimes it'll drop down to 0 until i start moving. Even after smacking the cluster a view times there isn't any difference. I'm pretty sure this is a wiring issue, perhaps it isn't getting enough power during idle and once you get the alternator spinning it gives enough juice. I'm not sure this is me just shooting the ˟˟˟˟. But anyways what wires should I be checking? Wires from the igniter, coil cluster? I'm not the greatest with electrical but I do wanna get the RPM guage working properly. If anybody can assist it'd be great.
FYI I have searched threw the forums and have only found a few post regarding this topic with no replies. Thanks.

 

Bumppppp

 

Tach signal comes from the black wire on the igniter. The alternator should have nothing to do with the tach.

 

nothing to do with the alt ...
The tach has a penteometer attached , so it is "adjustable"
you can simply "hook up" a volt meter in line , and get the correct RPM , then just adjust the penteometer to the correct setting


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i remember someone talking about rpm readout on guage giving a false reading... mine does it too but I know exactly how to fix it... inside the cluster it has a plastic adjustable screw to set the ohms resistance... this is used to calibrate the tach inside the cab... its on the writeup of the sr5 cluster swap