Megasquirt - wiring through the firewall

The Megasquirt is going to require some wires run through the firewall for grounds and to get signals from the new sensors. The best place on an NB to do this is through the big grey rubber gromet in the driver-side firewall where the stock harness passes through.


Here you can see the rubber gromet, just below and to the right of the the clutch hydraulic reservoir. I previously ran a vacuum line through here for my vacuum gauge.


I ran three 18 gauge wires (yellow) for the GM IAT sensor, and for the CKP and CMP signals from the NA 1.8L (1994-1997) Miata CAS sensor. I also ran two 14 gauge wires for the Megasquirt ground, and one 18 gauge wire for the LC-1 Wideband controller.

This is pretty easy to do by poking a hole in the gromet with a coat hanger, taping the wires onto the hanger, and pulling them back through the gromet.


I haven't made the connections yet, but I think this is where I'm going to go for the ground.

No comments:

Post a Comment