Charging light on upto 40mph

Thatsjustdandy · Apr 18, 2019

Hi all.

Got a problem with my series 3 SWB petrol. Only just bought it. The charging light stays on up to about 40mph, then goes out. Comes on again if I turn the headlights on or slow down. Could this just be dirty contacts on the connector on the alternator or is it more likely the alternator is clapped?

Bobsticle · Apr 18, 2019

Sounds like it could be the alternator. You have checked the fan belt I take it.

Thatsjustdandy · Apr 19, 2019

Bobsticle said:
Sounds like it could be the alternator. You have checked the fan belt I take it.

Yes, the belt is fine. I thought it was probably the alternator on its way out but will check the contacts. Did 35 miles like it yesterday but it started fine this morning. The alternator appears to be charging even though the light is on.

Bobsticle · Apr 19, 2019

Just stick a multimeter on it whilst ticking over. Mine gives 14 volts when charging.

Thatsjustdandy · Apr 22, 2019

Just measured mine at tickover, 13.94V with the charging light on.

Bobsticle · Apr 23, 2019

Try a length of cable from the light to the alternator to check the original isnt playing games.

wireman · Apr 23, 2019

Bobsticle said:
Try a length of cable from the light to the alternator to check the original isnt playing games.

It sounds like the wire from the alternator to the Charge Light is earthing out somewhere. As Bobsticle says run a new wire from the light to the alternator to see it that cures the problem and/or check the length of the original wire for chaffing etc.

Charging light on upto 40mph

Thatsjustdandy

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Bobsticle

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Thatsjustdandy

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Bobsticle

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Thatsjustdandy

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Bobsticle

De Villes Advocaat

wireman

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