Lights dim at 5000rpm

[steve 16v]

Driving home the other night, I noticed my headlights dimmed quite a lot as the revs went past 5k.

When the revs fall below 5k the lights get brighter-any ideas why?


Cheers,

Steve

 

[Alex H]

My lights do this too. If I put the windows up or down, they also dim, fairly noticeably.

 

[MT AUDIO]

windows drain a lot of power from the alternator,tis normal but above 5k ive never known it

 

[dwjeviltwin]

had it once on a truck from work, where the alternator had been wired up backwards, the quicker the engine reved the dimmer all the lights got..
Loads of fun at night on the M4...

 

[CupDude]

Falling asleep at the wheel

 

[steve 16v]

:lolup:

 

[bmh.01]

Possible alternator at a guess (voltage reg specifically). Could be miles off though tbh.

 

[steve 16v]

Chucked a meter on it last night, the voltage drops from 14v to 12v at 5000rpm.

Do I need a new alternator or is it the regulator?

 

[bmh.01]

Probably whole unit, it tends to go the other way if the volt reg is shot.

 

[Sash]

Regulator probably the cheaper of the 2 options!