JD_B18CDX

Hello,

I am installing a car alarm which montitors engine RPM.
Manual says install to negative side of ign coil OR tach input on the ECM.

I opened the distributor and found the negative side of the coil but decided not to tap there as there are bunch of other wires (along with negative wire I was looking for) which seems to be connected to a resistor. Also I'm avoiding to tap into the harness of the engine. I would rather tap in the chasis harness.
So this leaves me to either
1. Find the negative wire of the coil from the harness in the chasis harness
2. Tap to the ECM tach input.

Does anybody know where either of these wires are?

Many Thanks.

arcboy

I am not sure what your asking, but I just installed a MSD SCI on my B18C1 and had to connect to the negative and positive sides of the coil. But mi coil was labled neg. and pos. I had to cut both and splice additional wires to each side. I think I may have helped but let me know if I can help anymore.

JD_B18CDX

Thanks for the reply!
I was able to find the same thing you found earlier. When I opened the distributor, I can see a (+) and (-) for the coil.
But I did not want to tap to these wires becuase I will end up drilling the distributor housing to make way for the new wires.

Anyway, after a long time with a multitester and some patience, I was able to find the tach input.

Its a yellow wire with green stipes in the engine wire harness.
In the chasis harness, its a thin red wire with black dashes.

A continuity test will show that they are the same wire.


I tapped to the chasis harness and looks like everying is working fine.
I apreciate the advice and hopefully someday this information will be useful to someone else.