Tachometer

[Geoff]

Hello all, just finishing off a restoration on an S4, have driven to and from the technical control and a couple of small
local runs to show up any faults, so far nothing serious but one that has me a little stuck, the tacho does not work,
from very first start up in the garage to first run out nothing, then on the way back from the technical control it suddenly started working, got home stopped the engine started up again tacho does not work again a few days later
same thing happened went for a small run about a half hour and along the way tacho started working got home switched off, started up again tacho didn't work has happened 3 times now, strange problem any ideas,
thanks Geoff.

[oldelanman]

May just be a loose power or earth connection on the back of the tacho .. next time it fails try giving the wires a tweak if you can get your hand up behind the dash. Also try the panel lights, if the tacho light isn't working that would indicate an earth problem.

[ericbushby]

Hi Geoff,
As above, The first suggestion is always the same one :- Loose earth connection.
Those thumb nuts on the back of the tacho case can come loose easily.
Next:- Has the tacho got a reliable 12 volt supply when driving. Fix up something like two wires from the back of the case to a lamp lying on the passenger seat.
Best of luck
Eric in Burnley
1967 S3SE DHC