Electric Tachometer

[porscheboy1]

Will the 12 volt electric tachometer found in the 1965 356SC work in the 6 volt 356 cars? The bulbs in the instrument could be changed to 6 volts. The signal pulses from the coil could either in volts or amps? If amps (current) would it work?

[Three56SC]

While there was a 12 volt option for the 356, the majority of them are 6 volt. If your tach has been converted to 12 volt (or was an original and rare 12v unit), I don't think it will work properly on 6V. The wire from the tach to terminal 1 (or -) at the coil provides a path to ground at the points - this is what triggers the tach. The tach has voltage applied to it on the #15 terminal on the back of the tach.

[PD41]

I think it will work. You need to change the bulbs.

I have a 65 that is now a 12v car

The tach runs off the neg side of the coil.

[CASair]

check the back of the tach first. i doubt it's a 12v instrument. it was a very rarely ordered option on a push rod 356. Either way, i do believe it needs to be the same voltage the car is.

[PD41]

Originally Posted by porscheboy1

Will the 12 volt electric tachometer found in the 1965 356SC

A 65 SC came 6 volt. 64 and older was a cable drive tach.

There was some 65's that came a 12 v as a option.

Registry info;
From the Factory Parts Books it appears that the 12 volt electrical system in 356 Porsches, excluding the Carreras, first became available as an option with the 356 B T-6's. The availability as an option of the 12 volt electrical system started with the following chassis serial numbers:

Coupe #117 601
Cabriolet/Hardtop #155 601
Roadster #89 601
Hardtop 61 #201 601"

[PD41]

Check this out.

Bosch Electrical Parts for 356 Porsches

[porscheboy1]

Thanks to all for the information.

[Prsh356]

My friend purchased a new 65 SC sunroof in Germany and watched them build it he ordered it heavily optioned 12 volt was an option which was on his list of goodies along with headrests, camber comp. bar, electric sunroof + SC motor .

[bleucamaro]

After converting ours to 12v, we went with an electronic tach from palo alto speedometer. works good.