Erratic Rev Counter

[Richard Moore]

Over the last year my rev counter has become steadily more erratic. Symptoms as follows

1) The rev needle will flit from side to side before settling down at the right level
2) It will occasionally sink to zero and stay there for a while
3) It may do for this for ten minutes , a few seconds or not at all as takes it's fancy

There is no change in the engine revs or other dials while it playing up. The car starts fine even after a long journey.

The only other thing is that if the car headlights are on they will get brighter if the rev needle jumps to the right. Apart from that no other electrics seems to be affected.

The symptoms are steadily getting worse (albeit with no effect on general driving).

The guys at JZ are a bit non-plussed as it doesn't seem to suggest an alternator problem - they're suggesting a connection somewhere as nothing else is affected (apart from the lights). At the moment I'm waiting for it to either become a continuous problem so they have something to work with. We've swopped the rev counter and sadly it wasn't that - is it ever that easy

 

[bones]

Sounds like the voltage regulator or the alternator. If you have the alternator with the integarl regulator you can just replace the regulator. Before you do that clean every fuse and eletrical contact you can.