Tachometer wiring

[JohnMorin]

Hi

I removed the tachometer from my S4 some time ago prior to tydying up the wiring and fitting a new dashboard. Putting the new dashboard in, so far so good. The tachometer has two white wires coming out the back one of which goes to the ignition switch and the other to the security switch, but which goes where? Does it matter?

Attached pic shows back of tachometer with wires labelled A and B, can someone tell me which is which please.

The top of the tachometer is to the right of the image.

Thanks

John

[ericbushby]

Hi John,
Although my car is an S3, I thought the white wires were fairly short so that the Tachometer could be removed easily. It does matter which way it is connected and I think one wire had a male bullet and the other a female bullet connector. It will not cause any damage if incorrect, it just will not work.
Eric in Burnley
1967 S3SE DHC

[JohnMorin]

Thanks Eric.

Mine has male bullets on both wires.

John

[ericbushby]

Ah, that`s not very helpful then.
However if you can get access to it easily just connect it as seems most likely. It is a 50% chance it will be right.
If not, then the current pulse into the tach will be reversed and the system will ignore it but will not be damaged.
Eric in Burnley.

[pharriso]

Hi John,
I think one wire had a male bullet and the other a female bullet connector. ...
1967 S3SE DHC

Yes, my Tacho connections look like:

Not sure which connection went where though sorry...

[Andy8421]

Often worth searching the MG forums for these things. They have the same problems as us, but there are more of them....

Smiths Tacho wiring

Ignore the comments in the bubbles, its large black and red writing you need to follow.

[billwill]

You don't need to go to MG forums. There are many many many topics on this forum covering this issue. Do a search for Tachometer or just tacho.