I recently swapped a 350TPI for a 383stroker with a 750cfm carb. I was wondering if anyone knew what color the wire was for the engine tach so i could hook that up to the new distributor that i put in. Also i installed a crane hi-6 box for the inginition if that matters.Thanks

 

white

 

does this white wire have a plug-in on the end of it? I'm pretty sure i already tried a white wire and nothing happened.

 

The original plug that went to your coil. There should be two wires, one pink and the other white.

 

ok ill look-thanks

 

This is what i found, on the original distributor it has 2 plug ins. One was from the coil to the distributor with the pink and white wires. Other was a four wire plug in from the main wiring harness to the distributor.

 

There is another plug that goes to the other side of the coil. This one also has a pink wire and a white wire. Should come out of the main harness.

 

Looking at a wiring diagram......it shows a white wire going from the coil to the tach.

 

That is the one you are lookink for. It starts at the bulkhead connector and ends at a plug that went to the coil. There should be two coil connectors, one gray, and one black. You want the one that does not go to the distributor. You need the one in the main harness. It may have fell down behind the engine.

 

I searched and this is the best thread that might fit what I'm wondering. My Tach is really messed lol. It sits at like 3K RPM, then any slight twitch of the throttle and it pegs. So its always pegged. Could this be a wiring problem or is it the Capacitor or whatever behind the tach face? The Tach is removeable from the cluster isnt it? I have a friend that just did a 4th gen swap that I can get a new tach from if that is the case. Also, can I manually wire it easilly?

 

Make sure the tach matches the engine, i.e. V6 tach for V6 engine and V8 tach for V8 engine. The two are different, they work on different pulses from the distributor.

Sara Lou

 

ya, im pretty damn sure its a V8 tach, everything on the car says IROC, Vin n all. So I know its not a V6 tach lol. Unless someone was a total moron that owned it before me but I doubt it

 

Do you have a picture of what the OEM Tach wire is? i have jerry rigged a Tach to view shift points on my car. i wanna wire the oem tach up to my new distributor. i swap a 350 engine block from a k1500 and swapped out a new distributor for my car. i have a HEI distributor that has two wire tach piece that only requires power and tach speed. i have it wire to a sperate tach but wanna get rid of the OEM Harness and just hard wire to the OEM Tach. Im planning out building my own harness so can power only what i need

 

Wake up the dead 😆, if this is your profile 84 hei coil in cap white wire goes from c100 to hei terminal next to battery ignition switch voltage. Hei is marked

 

I have tried all of the OEM harness connectors to see if the tax would move. I cut a little wire off so I can stick copper to the plug terminals. It never worked but I wire an aftermarket and it works. I’m new to wiring cars

 

Ohm the wire from cluster to tach could be a bad stock tach. A fsm will help you a lot

 

Alright. Since this thread was revived from the dead, I’ll ask a question. A search for “tach wire” led me here.

So, I’m doing an LS swap. A white wire, D6, is coming out from the C100 harness. If this originally went to the distributor to monitor engine RPM, what exactly do I run that wire to now? Do I even need it anymore? I have a PSI wiring harness and ECU.

Any help is greatly appreciated. Thanks!

 

It's the signal input to your tachometer gauge in the dash. You hook it up to the tachometer wire from your ECM.

 

I'm guessing any square wave pattern signal that is the right frequency will give the correct reading right? The holley terminator x has a tach output that outputs a square wave. I'd think the OE signal from the coil is the exact same as the coil is turned off and on 8 times for every 720 deg of engine rotation. Am I correct on this or is there any filtering to the stock tach I need to work around.

I'm using the stock gauges for this swap until I have the money for a full holley 12" digital dash (and trying to figure out how to fit it cleanly)