Another electrical problem?

[svsdino]

My S today developed a new fault, while going along the charging light came on but the voltmeter still showed 14-15v ie still charging, but a few minutes later charging light went out, down to 11v and all the other gauges all went off- stopped reading. Then the charging light came back on 14-15v but still no gauges. strange thing is when the alternator light goes out and the voltmeter shows 11v my old idle speed valve problem comes back but when it's showing a charge runs fine?!
Anyone got any ideas?

[GreenV8S]

svsdino said:

My S today developed a new fault, while going along the charging light came on but the voltmeter still showed 14-15v ie still charging, but a few minutes later charging light went out, down to 11v and all the other gauges all went off- stopped reading. Then the charging light came back on 14-15v but still no gauges. strange thing is when the alternator light goes out and the voltmeter shows 11v my old idle speed valve problem comes back but when it's showing a charge runs fine?!
Anyone got any ideas?

The no-charge warning light will come on if the ignition switched voltage is different to the alternator output. These would normally be the same (0V) while the engine is stationary and switched off, and also the same (13.8V) while it is running. They will be different if the ignition is on with the alternator not turning, and if the alternator is turning with the engine off (you can see this as the engine spins down if you rev the engine then switch off).

The fact the output voltage stays high when the light comes on suggests that the ignition switched voltage is dipping. I would immediately suspect that nasty yellow connector between the ignition switch and the main loom, but it could also be a poor contact in the fuse box or any of the connectors in the loom.

[clarenceboddiger]

Looking at the diagram I would be looking at the connection of the green wire to the Hazard Flasher unit (I think it is on the terminal marked 54 or 34 my diagram is a bit fuzzy) This connection may run through the infamous yellow connector in the steering cowl so that may be a good area to look at too.

[spivvy]

check the connector under the stearing wheel from the ignition switch this can cause all sorts of problems

Edited by spivvy on Sunday 3rd May 10:54

[Gerald-TVR]

Yellow connector

[svsdino]

Thanks for the replies lads, actually the dreaded yellow connector has had a previous repair (pre me!) but I track it to the 10amp fuse which controls the indicators, warning lights and gauges! So she's sorted and looking great with her new paint job.

[Gerald-TVR]

Great stuff - so nice to hear of a sucess not a problem