Tachometer is jumping

[Jimmy_GTT]

Another strange electrical problem.
Ignition is on, but engine is not running. If I switch the indicator to any direction or start the wiper the tachoeter is jumping. Sometimes just a little sometimes nearly in the whole rev range.
What could it be?
I think it should be a bad earth. I have already checked and cleaned the body and the dashboard earths. Cleaned the battery conectors.
Any other idea what to check?

THX

[ranj]

i get the same problem every now and then .......the rev counter moving all over the place when key is in the on position but engine isnt running ...... i have noticed that when i press the brake pedal ... the rev counter stops moving about and returns to zero ..... Very strange problem :confused:

[bye_all_c_ya]

had this problem and found the plug in drivers footwell was to blame or earths in same area as i cleaned and checked both and dont get the problem anymore

[Jimmy_GTT]

had this problem and found the plug in drivers footwell was to blame or earths in same area as i cleaned and checked both and dont get the problem anymore

I have checked and cleaned the earths in both passenger and driver footwell.
Which plug are you talking about?

[Jimmy_GTT]

I have also tried to clean all the connectors, even changed the battery for a newer one but no success. If I disconnect the AEI the tacho stops jumping. I've also tried with another AEI same behaviour.