I placed this info on the New members forum before realizing it should be here...

My 96 Disco, 3.9 Petrol, has a Tach with a mind of its Own....Operates good until I turn something electrical on....Indicate to turn and tacho jumps in unison......Turn on headlights and tach jumps and steadys 1000 clicks higher......windscreen wipers create all sorts of flickering needle....wind the windows up and the tacho jumps when they reach the top....I suspect a faulty earth causing the Tach to act as the connection....
But any idea which earth connection to clean and tighten will be appreciated.
Thanks

 

Did you check the alternator? Thats usually a sign (going bad)when dealing with dash board gauges.

 

Could also be a starter issue.

 

I would suggest just taking it to the dealer, or to someone who works on Land Rovers.

:]

Happy Rovering



John-Robert

 

Check your battery connections and follow the leads back checking all connections. This is a tell tale sign of a failing alternator. When it goes, you tach starts jumping around. Check all of your connections under the bonnet first and you might go ahead and have your battery tested. If everything is still good, have the alternator tested.

Get back to us and let us know what you find. Highly doubtful it is your starter..

 

I would first say, it's not a starter issue as already posted.
Take your truck by an Auto Zone or any local auto parts store, most will do a load test for free on your battery and alternator.
Usually the alternator is failing when you are experiencing the problems you have described.