Voltage readings

[drivingfroggy]

I seem to remember reading a thread about volt meters, saying that it reads directly off the battery. When I switch on my lights the meter reads next to nothing. The alternator is obviously still charging, is this meter reading normal?

[martym]

I would say that the Alt is not quite charging enough its Volt meter is reading 12v + prior to switching lights on. What does meter do if you switch your fan on with out lights being on ?

[Barkychoc]

My voltmeter is pants, I just ignore it.

Didn't someone say odd readings could be the yellow connector under the steering column?

[GreenV8S]

The meter reads off the switched ignition circuit, which is supplied from the main power terminal on the starter so it's connected to the battery and alternator. But it's supplied by various switches connectors and fuses all of which will introduce a voltage drop.

The main connection between the ignition switch and the loom is a favourite cause of trouble.

The circuit also goes through the alarm which can play up.

Despite addressing all of these I still had a voltmeter that dipped alarmingly when everything was switched on, and recently I improved this by adding an earth at the alternator. The alternator is earthed by two pivots which are not clamped tight, and a bolt onto a bracket which in my case was covered in paint and rust. The end result was a random voltage loss here when the alternator was working hard. Adding a short earth between the body of the alternator and the mounting bracket has helped enormously.

Edited by GreenV8S on Tuesday 23 December 12:11

[clarenceboddiger]

drivingfroggy said:

I seem to remember reading a thread about volt meters, saying that it reads directly off the battery. When I switch on my lights the meter reads next to nothing. The alternator is obviously still charging, is this meter reading normal?

If it reads low when you switch other things on with the lights off I would look at the yellow connector if not it is probably the wiring connections near the Headlights.Mine were shot and new connectors really helped both with the light output and the voltage meter reading, but as GreenV8 says a good earth is a necessity from the alternator and will help all the electrical items in one go.

[drivingfroggy]

Thanks for all that advice.I'll check the earths and connectors. It's not too bad when I just put on the driving lamps and/or sidelights, so it could be something simple. Not sure if my heater fan actually works or not. I can get more hot air out of my a##e than comes out of the vents!
Cheers
Phill.

[Barkychoc]

drivingfroggy said:

Thanks for all that advice.I'll check the earths and connectors. It's not too bad when I just put on the driving lamps and/or sidelights, so it could be something simple. Not sure if my heater fan actually works or not. I can get more hot air out of my a##e than comes out of the vents!
Cheers
Phill.

My heater fan works noticeably when on full - it could be the switch mine is very dodgy.

[Gerald-TVR]

Yellow connector pic



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