[Peter Serio]

This answer will come in 2 posts.

The first post is written for '68 rally gauges but should be enough for you to figure out your 1970.


A non-gauge dash harness (1968-71) can be field converted from a standard gauge car to rally gauges as long as the wiring including the fuse block is still good.

IMPORTANT: you need to disable the twin green wire which runs out of the plug-in and over to the back of the ignition switch and then on out thru the firewall into the engine compartment to the coolant temperature sender.

This is something most people forget to do. A true rally gauge car dash harness has just a single green wire which connects the back of the gauge plug-in out to the sender via the firewall plug.

A car w/o gauges branches the dark green wire over to the back of the ignition switch & then on to the firewall plug. This is because when you crank the starter the temperature overheat lamp comes on bright red just to let you know that it is indeed working.

I have seen the dark green wire branched at the back of the key switch (1968) or the switch on top of the steering column (69-71) on all non-gauge cars. In some cases this wire could be forked at the dash gauge plug-in tab instead of the ignition switch plug.

All you need to do is remove the brass terminal from the black plastic plug-in behind the ignition switch and tape that off. DO NOT CUT THE GREEN WIRES!!!

Pete