Voltage regulator ?? - 390SE

[duncscz]

Is there one and of so, where is it ?

Seems I have the 'usual' gauges with minds of their own. The voltmeter flips side to side with the indicators and the temp gauge will happily drift up to 110 degs for a few secs before settling back at 90 (or even lower). There's no overheating problem. And all the gauges change slightly when the lights are switched on.

I've cleaned all the earthing in the engine bay and run a new earth directly from the battery to the bonnet release bracket in the cabin (which is the main earth point for cabin electrics).. but that's made no difference. The battery is ok and the alternator gives a healthy voltage.

So, I wonder if there's a voltage regulator somewhere ? Maybe within the voltmeter itself ?

Or , are there any other important 'earths' I've missed checking ?

TIA

PS . I tried an earth directly to the voltmeter from the battery .. but no improvement.

[Wedg1e]

There's no instrument voltage regulator like you used to get in the good old days!

A large part of the problem is that all the switched loads are handled by a pair of relays (labelled Ignition). Even though they're rated for 20A or sometimes 30A each, with all the resistance of the wiring loom there is an inevitable voltage drop when current-hungry circuits are switched on. The real fix is probably to rewire half the car in heavier-gauge cable.

Or in other words... they all do that, sir

[adam quantrill]

Try changing your new earth strap from the battery negative to the back of the engine block, as that's the reference point for the sensors (temp, oil at least) so you should eliminate some voltage drops. Hopefully.