12 volt 356 tach repro

Should be just 3-4 wires on the tach.  The important one is the + (Plus) which goes to a switch 12v (so only on when the car ignition is turned on), a signal from the coil which goes to the - (neg) coil terminal, and probably a gauge ground.  Other wiring would be for any gauge illumination lighting.  Do you have another tach that could be used to test to see if the gauge is perhaps bad but the wiring is good.  A tach with an internal blown diode could be the issue.

Here's back of SM tach - it does mention dip switch setting for # of cylinders. Ignore terminals for the turn signal, high beam or other indicator lighst to start. Does it have terminals marked or have a diagram?

Here's representative diagram - ignore terminal numbers -

Are the dip switch settings correct?

As mentioned above, borrow a tach to try the circuit out. If it works then you may have a blown diode or chances are the signal from the coil isn’t compatible with the new tacho.

I had a similar problem, l changed my dizzy and coil and the tacho stopped working. Tried another tacho and all worked as it should. So l had to send it of to NHS and explain the problem. They installed a new circuit board and all was working again. 

Greetings, We hooked up all the wires correctly. The problem is the tach

doesn’t move up normally with the revs. It seems to read write at idle,

but when you blip the throttle, it seems to be reading low. The old tach

Is the mechanical type.

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> On Aug 14, 2018, at 8:49 AM, SpeedsterOwners.com <**************> wrote:
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James posted:

Are the dip switch settings correct?

Have you checked the dip switch settings?  

Yeah...Sounds like it's set up for 6 or 8-cylinders

From SM site -

The DIN switches on the back can be set for 4, 6, or 8 cylinder engines. The proper setting for 4 cylinders is 1 - ON, 2- off, 3 - off.

WOLFGANG posted:

From SM site -

The DIN switches on the back can be set for 4, 6, or 8 cylinder engines. The proper setting for 4 cylinders is 1 - ON, 2- off, 3 - off.

^This. I had the same issue when I got my guages from Beck...

There are no dip switches on this tach. It does sound like it’s set

for the wrong # of pistons. Sierra Madre is bogus. No help at all.

The billed me twice for the oil temp gauge, and sent me another

item that nobody can figure out. It’s the size of a matchbox with

4 wires coming out of it. Plus, it was $180.00.

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> On Aug 15, 2018, at 10:14 AM, SpeedsterOwners.com <**************> wrote:
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The dip switches are typically behind a small rubber plug that has to be removed.  Maybe a small rectangular rubber plug?

Also, the small matchbox sized device with four wires sounds like the GPS sending device for the GPS driven speedometer.  

That’s pretty funny, we still have the cable driven speedo.

See what I mean about Sierra Madre?

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> On Aug 15, 2018, at 9:15 PM, SpeedsterOwners.com <**************> wrote:
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Did you pull the little square plug from the back of the tach and check for the dip switch settings?

I never knew about the plug. Sierra Madre was no help.

The dip switches are behind the plug that I have circled.  There should be three little switches and they should be set to: ON, OFF, OFF, from left to right (for a 4 cylinder engine).

And to answer your question from your first post on this topic, the best place to buy replacement gauges is from Beck Speedsters.  Contact Carey Hines.  Great technical support.

@ashcreek

 

Thanks, that looks like it.

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> On Aug 16, 2018, at 8:30 AM, SpeedsterOwners.com <**************> wrote:
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That did it, thanks

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> On Aug 15, 2018, at 10:48 PM, SpeedsterOwners.com <**************> wrote:
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Round of beer --- all around!

Not there thanks