Help Understanding Motronic

[75Carrera]

I've been watching the threads about the 3.2 Motronics.

Since my recent motor install the tach has been acting up (sticking or just falling to zero) and has now stopped altogether.
I saw several possibilites in the threads but so far haven't found it. It's not a loose connection (at least not at the tach) and my battery is brand new.

It sounds like other things in the electrical system can affect tachs. Is that true?
Could it be something as simple as the voltage regulator? I thought it might be the tach itself and I suppose it still could be. Any ideas on the best way to chase this problem down without spending a bunch to have someone else do it?

[Early_S_Man]

Donny,

Monitor your system Voltage while driving ...

If it is outside the nominal range of 13.2 - 14.5 Volts, then tachs can behave in various st range ways.

[75Carrera]

Thanks Warren,

You have been a very helpful member.
Without a gauge to monitor how do you check it?

[Hugh R]

Some auto stores carry digital voltmeters that plug in the lighter.

[Early_S_Man]

Donny,

It doesn't have to be done with a permanently-mounted gauge.

Analog or digital multimeter can be used with dedicated special test cord going from banana plugs to 12 Volt accessory plug, as in the pic below.

[75Carrera]

Just what I needed to know. Thanks guys!