Battery Light at high RPM

[Phil-E]

Hey there folks. As per the thread title while overtaking last night and proceeding to carrying on rev to give her a clear out I noticed the battery light coming on dimly (but quite prominently) when the revs got pretty high.Never noticed this before. Is it normal?Phil

[Wardy]

Wouldn't have thought that was normal Phil. Alternator related perhaps?

Steve

[Phil-E]

Sorry didn't mean normal in terms of doing it from the factory but more normal as in a "characteristic" of the car!

Yeh well the finger points to the alternator although it kicks of plenty of power etc. Could be the voltage regulator. As the alternator rotates faster it kicks out more volts and the regulator goes iffy some how. It is a common part to fail on these.

[TeflonTom]

is the belt slipping at all phil? normally the warning light is only on when there is nothing coming out of the alternator

[Phil-E]

Oh good point! I can't hear it... not over the engine noise anyway!

Now that I think of it the belt did slip first thing in the morning last week. Maybe I should check the belt adjustment and see where that gets me.

Thanks

Phil

[GentleGiant]

It could also be an indication that the alternator winding insulation is failing, the wire windings are coated in lacquer, if this is breaking down then the increased voltage caused by the high RPM may suddenly start arcing across the windings, reducing the voltage output.

(Had this on an old Renault).

A regulator usually just "fails" leaving you with no voltage at all.

PS, good to see the site up and running normally again

[djaychela]

Had this happen on the Felicia on Rally GB 06, it was actually over-charging leading to the demise of the in-car camera as well as a wonderful acidic smell. For obvious reasons just replaced the entire unit.

[lykos]

Sorry for the 1 month delay! philje123 I have had the same problem with you three times in the past.It was the precursor for the automatic voltage regulator failure.Unless you replace the A.V.R. you will see the battery light from barely visible gradually going to brighter,and lit up from lower rpm,until it finally stays on permanently (which is a bad thing for your alternator to allow to happen).For your information,draining current through a damaged A.V.R. contributes to faster wearing of the alternators conductors (and the A.V.R.'s brushes of course but it doesn't matter if is going to be replaced anyway).

[Phil-E]

Cool.

Well I think it might be time for a new voltage regulator then as I don't want blown electrics and a fried ECU!

Phil