I can't find the tach wire to splice into so I can install the tach, I went down to the dodge dealership, and they said it's a light grey and blue striped wire in the powertrain control module(1), but I spliced it, hooked it up and I got nothing. I have an Autometer tach...can anyone help?

 

Forgot to add, my car is a 1998 R/T (DOHC), MTX.

 

If you pull the top of your dash off, you just pull up on it as it is only held down with clips, you will find a wire harness under there.

Right in front of the driver you can dig into that wire mess and pull out that wire, it will still be grey with the blue strip. I used that becuase it was much simplier than going to the pcm.

Im going to assume the tach has 4 wires.

Illumination
Power
Signal
Ground

The illumination wire I tied into the headlight switch so it goes on with the headlights. The signal under the dash, ground I screwed into some metal near the steering column. For power I ran that into the fuse panel by the driver door inside the car and hooked the wire to the wipers fuse since wipers only work when the ignition is on.

Also, make sure your tach is set to 4 cylinder mode if it has a selector. (on the back usually)

If that doesn't work at all, then you might need a tach adaptor.

Try it out and get back to us!

Good luck

 

I got nothing with that grey wire you're talking about.

 

What do you mean. You don't understand? Or was there no signal from the wire?

 

No signal.

 

bump.

 

does your car have a factory tach.....if it does then you have to disconnect it....other wise the stock tach will ALWAYS override the aftermarket

 

I never heard that...do you know why?

 

no im not sure....but it took me about 3 days to figure it out.....and thats why i cut the tach wire from the clip behind the gauge cluster and wire the aftermarket one in there......if at any point you have a stock tach in the cluster, an aftermarket one will NOT work unless the stock one is disconnected