25 replies to this topic

[sweetser]

Thanks mate, so i can just wire the black into the wiring loom were a solid back wire is already?

Cheers Luke.

[HARBER07]

Yup

[sweetser]

Cheers.

[mighty mini jack]

Bump on request __

[sweetser]

Can any one help?

This is how we trie wiring it up

A (Green)- goes to the negative side of your coil.

B (Black)- goes to an earth (attatch to body)

C (Red)- goes to a switched live on your fusebox (Switch live should be the fuse on the fusebox with a green wire in one side, white wire on the other.)

The other red is an illumination circuit. the red goes to a live and the black to an earth... wire it to your dash illumination circuit.


But it dont work.

Any ideas?

Cheers Luke.

[HARBER07]

Looks ok to me luke, just an idea but is it because your running a ballasted ignition setup?

[sweetser]

I dont know

[HARBER07]

LOL! Well thats what i would try after double checking the connections (non ballasted coil etc, luke knows what im on about with this lol).

[sweetser]

LOL! Well thats what i would try after double checking the connections (non ballasted coil etc, luke knows what im on about with this lol).

Err yeah?? Lmao

Joking lol

Edited by sweetser, 02 February 2009 - 09:52 PM.

[dklawson]

Ballast vs non-ballast does not matter in this case as the connection is to coil (-). The tach will be looking for swings between 12V and 0V. When the points are open you will have 12V on the coil (-) terminal, when they close you will have 0V. The terminal that will be effected by the presence of the ballast resistor is coil (+)... which will read less than 12V and more than 0V when the points are closed.. If you have a multimeter you can test this yourself quite easily and I'll be happy to explain the steps to perform this test if you're interested.

The wiring described above matches the instructions you posted on the first page of this thread. I suggest some simple tests. Inside the car, switch on the ignition and use a multimeter to confirm you have 12V between the red and black tach wires. If you do not, you know you've either chosen a bad earthing point of that there is a problem with the fuseblock connection you selected. If you have power but the tach does not work, check the wire going to the coil for continuity. Perhaps it is disconnected somewhere or broken inside the insulation.

If you still have no luck, consider testing the tach outside the dash. Remove the tach from the dash and take it to the front of the car. Your photographs show the tach has two black wires, two red wires, and one green wire. Connect the two black wires to each other then run a short length of wire from them to a GOOD earthing point under the bonnet. The horn mounting bracket stud is one possibility but you pick what's best for you. Take the red wires and twist them together. Run a short length of wire from the twisted red wires to an electrically hot connection under the bonnet. For now this does not have to be switched or fused. I suggest the place on the starter solenoid where all the brown wires converge. Lastly connect the green wire to the coil. As before, use the coil (-) terminal (where the white/black wire connects for the points).

With the tach hooked up temporarily like this, start the engine and return to the front of the car. The tach should be working and it's illumination light should be on. If it isn't, you probably have a dead gauge.

[sweetser]

Cool thanks for that mate, ill give it ago when the snow is gone