Should this be connected to something?

[Richard Edwards]

Looks like a condenser?

Car starts and runs OK but tacho does nothing at all

Wondered if this might be why?

If I remove the dash is there a test I can do to identify why the tacho doesn`t work

Duff unit versus not receiving a signal?

Pressure gauge, ammeter, temp etc. all work

 

[quattro]

It's a radio surpressor, just there to reduce noise on the radio, although it won't work because it's not connected.

 

[Phil Robson]

The loose end wants a female spade connector on & attaching to the double fitting on this side of the coil.

 

[Richard Edwards]

It's a radio surpressor, just there to reduce noise on the radio, although it won't work because it's not connected.

Nothing to do with the tacho not functioning?

 

[smokin1942]

Nothing to do with the tacho not functioning?

Can't help as Electrickery is a foreign country for me, but try the Search box on this section with "signal to tacho from ignition".
The same search on Google produces some possibly relevant stuff on 'lotuselan.net' and 'spiyda' forums

 

[quattro]

On my car, which is not necessarily the same as yours (What's your chassis number?) the two wires in your picture are black and white. One comes from the coil, and the other one goes to the tachometer. The white wire on your tacho is the 12V feed which should be live with the ignition on. The wiring is slightly different if you have an older car, hence the need for the chassis number, or at least the suffix.

Please note if you are looking at the HBOL (I wonder why it's called the Haynes Book of Lies), page 200, i.e. wiring diagram for an E suffix like Sparky, number 34 is the tacho, not a ballast resistor like it says in the Key (Oh that's how )

 

[Richard Edwards]

Chassis number is this (early 1972 first registered)

 

[quattro]

Can't see the picture, just the suffix will do.

Richard

 

[Richard Edwards]

Can't see the picture, just the suffix will do.

Richard

It`s a B Richard

 

[quattro]

It`s a B Richard

OK, different to mine then. The power comes in from ignition on a white wire directly to the tacho, so if you check this it should be live. A white/yellow wire comes out from the tacho and feeds the coil. So, if your engine runs and no one has messed with the wiring, it points to an internal fault with the tacho. I hope that makes sense?

Richard

 

[Richard Edwards]

OK, different to mine then. The power comes in from ignition on a white wire directly to the tacho, so if you check this it should be live. A white/yellow wire comes out from the tacho and feeds the coil. So, if your engine runs and no one has messed with the wiring, it points to an internal fault with the tacho. I hope that makes sense?

Richard

I think it makes sense Richard

So if I check the white wire at the tacho and it has has 12v the tacho is the culprit?

 

[quattro]

Sorry Richard, I didn't see this.

Your tacho feeds the coil, so if it's not working, it's an internal fault - UNLESS someone has changed the wiring. In a car of that age, it could have been rewired, someone could have changed the tacho and wired it accordingly, etc.

There should be a white wire with a yellow tracer coming from the back of your tacho. If there is, turn the igntion on and check that the terminal is live. Then check the +ve side of the coil is live, where the white/yellow wire should go. If so, remove the W/Y wire from the tacho and check the +ve side of the coil again. It shouldn't have any voltage going to it. If this is all OK, then it looks like it is the correct wiring, and you have an internal fault.

If anything is different, post again.

Cheers

Richard