So I just swaped my car to tpi from a carb. And am having trouble wireing the box in, in the diagram for it it only shows one red wire from the harness but two from the coil my question is what do I do with the other red wire that goes from the coil to distributor? I hooked it in with the red wire from the harness and the car runs but the tach jumps around when you give it gas? Any ideas would be great thanks.

Jesse

 

Should have a power and a tacho wire from the stock harness going to the red and white wires on the MSD box.

Org and black wires from the box go to the coil terminals , pink and white go from coil to dist

 

Get the "plug and play" harness. Thats what I did, no cutting or nothing.

 

that's what I might do if I cant get it fixed in the next day or so

 

You haven't answered if you have it wired up as I said ?
The MSD PnP harness just does the same " for dumbies "

 

You mean for people who are smart, and don't want to cut theirstock harness which is old and fragile...

 

The car runs but the tach only works at idle and when I give it gass it jumps around

 

I thought I might hace somthing in the wrong spot and thought the harness might fix it

 

Get a MSD tach adapter. Or you might be able to get away with installing a 10K resistor inline with the tach line.

 

Where is the tach hooked up? Is it to the dizzy or is it to the box? I have a 6al and the tach line is in the factory spot(to the dizzy) and it works fine. I know if you run it to the 6al box it can be hit and miss.

 

Mine is connected to the distributor. I think the white or gray wire.

 

It is hooked up so that the white wire from the harness and the white wire from the dizzy both go to the msd box's white wire like the diagram shows

 

And same for the red wires they both go to the red wire from the box and the brown tach wire out of the box is not being used right now

 

Did you get this fixed yet?

-(white wire is not used with stock tach, fyi)

 

Yes it is. Take a look at your plug and play harness. The white wire goes to both the msd box AND the tach. Some people wire the tach straight to the msd box via the tach signal wire, which I have seen has been hit and miss.

http://www.msdignition.com/uploadedF...structions.pdf

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