9 replies to this topic

[Coolingthunder]

So I have a Caerbont automotive (Smith's) 80mm tach that I have to wire up in my car. It has 6 wires:
Brown/slate: Pull up for ECU output
Red/white: gauge lighting
Red/blue: tacho out from ECU or contact breaker or alternator W terminal
White/black: same but high sensitivity
Black: ground
Green: switched ignition positive 12V supply.


So now my question: the car obviously has no ECU (88 Mini( so do I just wire gauge lights, contact breaker (via the coil??), The ground and power? So using only 4 out of 6 wires?

Thanks!

[Spider]

Yes, you would only use 4 wires;-

 

Red / White     Lighting
Red / Blue       Points. This connects to the wire from the Coil to the Points.
Black               Earth
Green              Switched + ve

[Coolingthunder]

Okay, great, just what I needed!!!

Just to be sure, the tach sending lead goes on the coil negative right?

[unburntfuelinthemorning]

Okay, great, just what I needed!!!

Just to be sure, the tach sending lead goes on the coil negative right?

If the negative terminal of the coil is connected to the contact breakers then yes it does.

[Coolingthunder]

Now I have a problem with the gauge lighting... I spliced into the red/green wire for power and black for ground but no dice on the backlight...

[unburntfuelinthemorning]

Are you sure you got the red/green wire and not a green/red wire by mistake.  If you got the green/red one then the backlight will flash in time with the left hand indicators!

[Bobbins]

Now I have a problem with the gauge lighting... I spliced into the red/green wire for power and black for ground but no dice on the backlight...

 

Why have you used a red/green for power? The feed you need is a solid green (ignition switched live).

[Spider]

The Back Light on the Gauge is the Red / White wire. In the Loom on the Car, the Wire to spice that in to will be either Red or Red / White.

[Coolingthunder]

Nevermind, just a bad connection caused by the superseal connector I was using.problem solved!

[Coolingthunder]

Now I have a problem with the gauge lighting... I spliced into the red/green wire for power and black for ground but no dice on the backlight...

Why have you used a red/green for power? The feed you need is a solid green (ignition switched live).

Yes, for the lighting you need to use red/green because otherwise the gauge lights would be on non-stop (or well, anytime igniton is on)