Disco 1 Built Date 6/91 tachometer

I am making a thread to ask if anyone here may have/had the same problem i am having with my tacho atm. On a normal day the rev counter is showing at least twice the rpm to what the engine is actually doing.. On a not so normal day it flicks up and down the tacho count in time with the indicators .. I am not sure where to start looking to sort this one out.. I would appreciate any suggestions on what is going on/ where to start to fix this ?

I would guess that something else has caused a bit of heat in the wiring loom, fusing two cables together? But that is just a guess. Does everything else work ok? Do any electrical circuits have too big a fuse?

Everything works yes.. Even the tacho, it just reads to high.. I have looked at the fuses in the last 24 hours checking to see that each fuse is the correct amp, but in doing that i did only use the fuse location map sticker that is on the back of the removable fuse cover panel (which is colour coded)I did not check using a disco 1 workshop manual (Oh and i forgot to say that we are talking petrol 3.5 v8)

The tachometer is not driven by the voltage but frequency from AC part of the alternator before being recified to DC .This supply to tachometer is taken from the seperate connection on the alternator , therefore the speed of the alternator will determine the tachometer reading--Taken from Forum

but also with the indicators having a effect on the dial, i would suspect that there is a common bad earth somewhere.

is it an orig alt with the correct pulley size? someone might have stuck on a 200 or something with a different size.

I am yet to check on that one trax.. While i am here.. i will ask if you have an idea on what size the original should be ?

just measured mine, 300tdi M reg,

62mm

Thank you so much heggars ..Takes notes.. I am yet to get check this as of yet. I spent most of my free time today on a dry run winch fitting.. Before n after pics follow if you are interested. http://i950.photobucket.com/albums/...obile Uploads/20141231_102105_zps3f0dd298.jpg

http://i950.photobucket.com/albums/...obile Uploads/20141231_172955_zps3f8ad8ca.jpg

your welcome, just hope it's the right size.
wish i could afford some new toys

My Gf brought me that winch for x mas .. As for new toys, I find a lot of stuff on wrecks.. Stuff i can clean up and fit myself.. This one will be added in the not so distant future http://i950.photobucket.com/albums/...obile Uploads/20141230_194244_zps23fbd7ab.jpg

Looks like you fitted the hause too high up in that photo?

And as for this.



NO, no, no, it just begs to be ripped off or bent buckled and phucked at the slightest hint of a bit of play time in the mud, guess how I know that