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I have a 2000 gt does any one know what color the wire that comes out of the CPU reads the rpm? I'm trying to wire a window switch
 

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^+1, there is no conventional tach signal produced by the PCM. The instrument cluster tach is driven via digital data delivered over the SCP (OBD2) data bus...
 

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There might be another way to, just have to do some research, I know I've always been told on coil pack and cop cars you have to use the adaptor to get a rpm signal
 

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I've. Been reading and a lot of people say you can tap into a coil wire the red and white one on the #8 coil
You can if the device you are connecting to can deal with that signal, and can be adjusted to handle a 2 revs/pulse input (any single cylinder only fires once per two engine revolutions on a 4 stroke/cycle engine).

Another complication that some tach-like devices can't handle is that at idle, and up to 1200 rpm, each COP fires rapidly three times at each spark event, as shown below:



This is to improve combustion and emissions at idle and low engine speeds. It can confuse some external devices if they do not filter out the repeat firings.
 
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