Bigmikey65

My ‘70 W-30 is close to being finished after a complete restoration. Everything was restored to factory stock specifications. It’s a 4 speed car with 3.42”s and stock SSII’s with 14 inch repro Polyglas GT’s. The speedometer operates correctly up to 60 m.p.h. and then the needle spins completely around, past the 120 m.p.h. marker. Any ideas why this would happen ?

Also, my Rally Pac gauges were gone through and restored. After installation everything was working fine but now the tach is not working. Where should I first start looking to resolve this issue ?

Thank you, Mike.

leftlaneonly

I would check grounds and see if they replaced the little red junk v6 or v8 jumper with a soldered wire jumper.
when you put it back in were the copper fingers at the connector in good shape , maybe bend them up a little to make a better connection.

VC455

Mike,

The speedo sometimes does that due to wear allowing spinning parts to touch. A local instrument shop fixed mine at low cost.

As you realize, the tach connections are simple. You can easily check them by removing the tach, connecting a length of wire between the coil negative and the tach terminal, and connecting a short ground wire to the dash structure.

Except for the coil connection, you can sit in the driver seat to do this and test the tach. It's a fast way to eliminate wiring problems as a potential cause.

Gary