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Gazza96
4th May 2012, 05:32 AM
Hi All
1995 patrol deisel - start up in morning the tacho isnt working, Then after 5 mins of driving pops up and works fine, just started happening everything appears fine.

AB
4th May 2012, 05:37 AM
Hows your battery going, does your car "just" turn over in the morning?

I noticed when my alternator died the other week the tacho was the first thing to stop working. This would also explain why it starts working after 5 minutes as the alternator charges the battery back up after getting sucked dry from the crank.

I'm sure there could be other ideas so hang tight mate from other members.

As a quick check do you have a good battery you could steal from another car to try out or just check the voltage drop when you start it up in the morning.

Gazza96
4th May 2012, 07:18 AM
Hi AB
i turn IGN on for 10 sec let glow plugs warm up and starts first time , ALT is working the charge is showing about 14 volts headlights dont dim at idle. was wondering how the tacho gets its signal from for the RPM the engine is doing as theres no coil for signal?

White Elephant
4th May 2012, 03:45 PM
I will be watching this thread with great interest. My tacho hasn't worked for quite a few years now, I replaced the sensor behind the injector pump timing pulley when i rebuilt the motor hoping that would solve the problem, but alas it was just a $300 waste! It definately has to have something to do etiher with the actual gauge, or something electrical in between. I am retarded when it comes to Auto electrics aside from really basic stuff. Regardless, I hope you can fix it and I hope someone comes along with the perfect solution! :)

garrett
12th May 2012, 01:14 PM
i took mine apart and put some contact cleaner on the plugs which managed to fix the problem a few years back and shes still running

TEA20
20th August 2012, 11:20 AM
Hi guys, I have a 2006 td4.2 and i have a simular problem exept mine also makes a horrible slapping rattle sound up font top of the engine at startup, oil pressure light gose off after a second or two noise is still there, Tacho still not moving yet either. give it a good rev about 2500 noise quiets down to almost nothing,tachostarts to work now but not accuret at all. ounce engine is hot all is good, only very faint noise at idle.
Sorry Gazza not trying to steal yor thread, I just thought that the sender unit may have somthing to do with my problem as well and was woundering if and where the sender unit is too.

Mark