Thread: 300tdi Discovery tachometer playing up

Unless I am mistaken the Disco tachometer feeds from the alternator. Your symptoms suggest either a loose drive belt or a poor connection, or possibly a faulty alternator.

John

Very likely it is the connection at the back of the alternator,just a case of taking the rear plate off ( that thing that look it protects it, set off slightly) and cleaning the connections,
as JD said, check the drive belt, it may be past it use by date



john

The feed for the tacho is a female spade connector onto a male spade at the back of the alt. If, after you give it a bit of clean and a tighten with some needlenose pliers, it still plays up - try this:
(After disconnecting battery of course)
Undo nut and remove spade adaptor from alternator.
Make short lead with 20amp rated insulated wire, crimp eye terminal one end, crimp male spade at the other end, solder if you wish.
Bolt eye terminal into place, and connect male to female spade. Use heatshrink or electrical tape to protect spade joint. Tiewrap away from alternator alongside engine loom.
Now the spade connection is away from vibration, dirt and water. It won't vibrate loose or corrode.

And if it all goes to poop with the alternator, I've recently converted a Magna V6 Bosch unit to work, including the alternator signal wire addition.

http://members.optusnet.com.au/mac.man/alternator_swap/

Thanks for all the advice. I'll keep you all updated.

How easy was that - just slip off the spade connector and give it all a clean.

I feel stoopid for asking!

Macman said!
And if it all goes to poop with the alternator, I've recently converted a Magna V6 Bosch unit to work, including the alternator signal wire addition.

Your talking V8?
as the TDi mount on the other side so a lot harder to do..?

Yep, V8.

There's nothing that can't be achieved with enough money or dynamite. or just some tinkertime with the welder.