tach bypass, resistance wire, coil pwr

[SteveO_71]

I've been reading posts in an effort to educate myself regarding my 71.

It seems that one of the issues is that IF the original tach goes bad (opens), since it is in series with the starting circuit, the coil will get no power and the car will not run.

I understand the issue and wanted to come up with a fix in case this eventually happened to me.

The real fix is buying a new improved tach from RCCI but until that time occurs.

So, assuming the tach goes bad...

From the attached wiring diagram, I see I can jumper the bullet connector that attaches to the tach.

Does the gauge cluster need to be removed to access this connector or can it be gotten to from under the dash?? Seems tight under the dash.

As a tempory fix, could I tap into the +12 line going to the pertronix (which I have) and connect this to the + side of the coil? Or + 12 side of the starter solenoid? Maybe get a 2 ohm higher wattage resistor and put that from the + 12 to the + coil?

Am I thinking along the right lines?

Thanks!

PertronixMustangXR7WithTach.pdf

 

[jbojo]

If you wire up your system per the schematic you attached all you would have to do is bypass the tach if it goes bad. If you use the RCCI conversion they supplied me the jumper because you have to bypass it anyway.

http://rccinnovations.com/Instructions/XR7Tach.pdf