Skip to main content

I’m in the middle of converting a 356 to 12 volts. I purchased a tach from Sierra Madre, and can’t get it to work.

I’ve tried to discuss the problem with them, and are completely disappointed with the results. They have no tech

support. Is there another place where I can get this gauge?

Attachments

Images (1)
  • 7E169BC9-A681-44ED-B602-ED088313768F
Original Post

Replies sorted oldest to newest

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 -

Attachments

Images (1)
  • mceclip0
Last edited by WOLFGANG

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. 

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.

Sent from my iPad

> On Aug 15, 2018, at 10:14 AM, SpeedsterOwners.com <**************> wrote:
>
>

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

C580D9A2-9648-4904-833F-BC65E95618B2

200B7E8F-4757-4ADA-99D3-0A18F0E0B1C1

 

Attachments

Images (2)
  • C580D9A2-9648-4904-833F-BC65E95618B2
  • 200B7E8F-4757-4ADA-99D3-0A18F0E0B1C1
Last edited by James
Post Content
×
×
×
×
Link copied to your clipboard.
×
×