flickering interor lights heater fast slow

[Welshy_Pete]

The interor lights have started flickering on idle. Also the heaters go fast and slow some times as well. The driving lights do it some times as well.

When you rev up slightly the interor lights stop flickering.

The altanator belt it tight. The lights don't flicker with the engine off.

How do you check the voltage regulator working ok or not?

The battery when engine off needs to be 12.5v or higher?

When the engine running 13v to 14.5v?

306 hdi

[spider]

Voltages seem about correct.

Check the main earth leads from the battery, especially the connection on the gearbox as it can corrode a bit here due to battery acid runoff, the one on the inner wing (I think its there, the body earth) also can corrode a bit. To be honest if in any doubt unbolt them and clean them and pop them back.

This might sound an odd question but does your rear wiper work ?

[Welshy_Pete]

Voltages seem about correct.

Check the main earth leads from the battery, especially the connection on the gearbox as it can corrode a bit here due to battery acid runoff, the one on the inner wing (I think its there, the body earth) also can corrode a bit. To be honest if in any doubt unbolt them and clean them and pop them back.

This might sound an odd question but does your rear wiper work ?

The rear motor wiper packed in a while ago.

I started and run the car 5 hours ago. I've just checked its saying 12.30v now. The weather colder now as well.

But when the car running it goes up to 14.5 to 15v+

[spider]

The running voltage seems reasonably correct to me.

I only asked about the rear wiper as water can get into the relay (inside the trim in the back hatch next to the wiper) and that can cause some very very odd effects such as the charge light coming on / off. Seen a few do this and unplugging the relay provided a temporary cure.

I'd check the main earth leads as a starting point then as above, then if they are sound (also check the heavy output lead bolted to the alternator is not corroded too) it may be time to think about a replacement alternator...

[white exec]

Wonder where that particular alternator is sensing battery voltage?
If rear wiper relay fault can affect Charge light, does that then have an effect on the alternator, as c.l. is often a key connection for alternators.

[Welshy_Pete]

The running voltage seems reasonably correct to me.

I only asked about the rear wiper as water can get into the relay (inside the trim in the back hatch next to the wiper) and that can cause some very very odd effects such as the charge light coming on / off. Seen a few do this and unplugging the relay provided a temporary cure.

I'd check the main earth leads as a starting point then as above, then if they are sound (also check the heavy output lead bolted to the alternator is not corroded too) it may be time to think about a replacement alternator...

I took that blue relay out of the boot the plastic cover had come of and inside the relay had gone so left it out.

Just checked the battery over night it was 12.30v now 12.26v. So the battery seems fine at the moment.

I've tried the original battery and another good battery both do the same thing flickering lights and heater speeds.

So how do I test or check the voltage regulator?

I have test the altanator with multimeter on battery + and - it charges up to 14.30v to 14.60v. But it drops every few seconds from 14.60v to say 14.37v then back up again. So there a drop age going on with the altantor?

[Welshy_Pete]

The running voltage seems reasonably correct to me.

I only asked about the rear wiper as water can get into the relay (inside the trim in the back hatch next to the wiper) and that can cause some very very odd effects such as the charge light coming on / off. Seen a few do this and unplugging the relay provided a temporary cure.

I'd check the main earth leads as a starting point then as above, then if they are sound (also check the heavy output lead bolted to the alternator is not corroded too) it may be time to think about a replacement alternator...

I took that blue relay out of the boot the plastic cover had come of and inside the relay had gone so left it out.

Just checked the battery over night it was 12.30v now 12.26v. So the battery seems fine at the moment.

I've tried the original battery and another good battery both do the same thing flickering lights and heater speeds.

So how do I test or check the voltage regulator?

I have test the altanator with multimeter on battery + and - it charges up to 14.30v to 14.60v. But it drops every few seconds from 14.60v to say 14.37v then back up again. So there a drop age going on with the altantor?

It looks to me its now pointing towards the voltage regulator with it charging up 14v+ then jumping up and down the volts?

[Peter.N.]

Voltage should be 14.4v pretty well all the time unless you have just started it, sounds like an alternator problem.

Peter

[spider]

I'd agree its time to look for a replacement alternator.

[jgra1]

I have flickering on my x7..

I was going to check the earth points but can't help pointing a finger at the alternator .. may send it off to be tested one day soon..
john

[white exec]

Unstable voltage at idle seems to be something of a minor epidemic at the moment. There had always been a tendency for alternator output to be a bit less than perfectly smooth at very low revs (engine idling), often causing visible flicker on the interior overhead light. Increasing engine revs slightly makes the flicker disappear.

(Some V8 engines used to suffer from inadequate alternator output, because of their leisurely tickover speed. Fitting a slightly smaller alternator pulley was a common fix, to increase alternator revs. I'm not suggesting this as a way forward here.)

It has been reported that some poorly-refurbished (exchange) alternators perform badly with respect to stable and dependable output. Where this problem occurs, I wonder whether the alternator is OE or not?

[Welshy_Pete]

Unstable voltage at idle seems to be something of a minor epidemic at the moment. There had always been a tendency for alternator output to be a bit less than perfectly smooth at very low revs (engine idling), often causing visible flicker on the interior overhead light. Increasing engine revs slightly makes the flicker disappear.

(Some V8 engines used to suffer from inadequate alternator output, because of their leisurely tickover speed. Fitting a slightly smaller alternator pulley was a common fix, to increase alternator revs. I'm not suggesting this as a way forward here.)

It has been reported that some poorly-refurbished (exchange) alternators perform badly with respect to stable and dependable output. Where this problem occurs, I wonder whether the alternator is OE or not?

I've checked its a genuine valeo.

[white exec]

Might be worth getting it tested/checked by a reputable workshop. Quite possoble that a Valeo (or any other main brand) has been refurbed at some point, with inferior regulator components. Worth checking, too, the connections at the alternator, and at the battery terminals, to make sure they are all clean.

The battery voltage itself will not flutter - only the alternator output can do this.