renix coil, which wire for tach

Hooking up an aftermarket tach. Anyone know which wire is negative side of coil?

1987 Cherokee with renix coil. Has 4 wires on the coil,

3 wires together in one plug
Yellow, green/white, black

Center plug is a two wire plug but only one wire in connector and it is yellow/white

I have also installed an afermarket tach on my 86 2.5L and I believe they have the same coil. I think you coil looks like this one . If it does what i did was wrap the tach lead around the negative termainal of the prongs that you see sticking out. It holds itself in fine and thats what the autogauge instructions told me to do. I'm sure you will find out its nice having a tach.

If I remember right, the coil was marked?? And,,,, it seems like it was the front most terminal when looking at the mount.... Don't quote me, but I think that is right....

tgoff said:

I have also installed an afermarket tach on my 86 2.5L and I believe they have the same coil. I think you coil looks like this one

. If it does what i did was wrap the tach lead around the negative termainal of the prongs that you see sticking out. It holds itself in fine and thats what the autogauge instructions told me to do. I'm sure you will find out its nice having a tach.

Click to expand...

Mine has a straight row of round terminals that hardshell connectors attach too.

I took the coil off and there are no markings. But there is one flat spade terminal above that row that was not attached. I bet that is where the factory tach's hooked up.

Anyone else know if that is correct?

Figured it out. It was the green/white wire which is the very end terminal.