Pagoda SL Group

W113 Pagoda SL Group => Electrical and Instruments => Topic started by: Benz280 on June 22, 2022, 22:18:27

Title: Lights gently Flicker at Idle
Post by: Benz280 on June 22, 2022, 22:18:27

Have noticed that at Idle and running lights may gently flicker, not completely on and off. Can hear a slight a slight draw on the engine when this occurs.
Just curious if this is a sign of something bigger .   

Title: Re: Lights gently Flicker at Idle
Post by: OZTURK71 on June 23, 2022, 06:23:43

I think it's a charger (Alternator) related problem.

Title: Re: Lights gently Flicker at Idle
Post by: Kevkeller on June 23, 2022, 17:54:17

Could be the rectifier diodes in the alternator.

Title: Re: Lights gently Flicker at Idle
Post by: Charles 230SL on June 23, 2022, 18:18:42

Quote from: Kevkeller on June 23, 2022, 17:54:17

Could be the rectifier diodes in the alternator.

yes, Kev is right. I had a bad diode in my old 35a alternator. Before the diode died completely (and my red alternator light illuminated), my lights would dim a tad at idle and flicker brighter when I increased RPMs. I rebuilt my alternator and went ahead and replaced the external regulator while I was at it. 

You can buy a new or rebuilt alternator for a fairly reasonable price.

Title: Re: Lights gently Flicker at Idle
Post by: georgem on June 24, 2022, 02:27:28

Just to depress you a tad, perhaps at my expense - I had the opposite problem - the alternator light wouldn`t come on at all. A the same time the battery "failed" . So first port of call was the battery place - yes mate, your battery is dead - ....new battery..... no change to the light. Next the auto electrician - yes mate your alternator is toast - reconditioned the alternator and put in a new regulator (and yes, they aren`t too expensive)   Ah, that should fix it  NO.....hmmmm whats left ........... the alternator dash bulb of course - sure enough after going through the convolutions of getting the central instrumental cluster out - yup the bulb was blown. Now I wake up at night thinking that if I had bitten the bullet and started from the other end of the chain all would have been good for a $1 bulb :-\

Title: Re: Lights gently Flicker at Idle
Post by: Cees Klumper on June 24, 2022, 11:31:17

If it makes you feel any better George - given your battery had died, there must have been a real problem with either the alternator or the battery, in addition to the light having failed.
Generally I tell myself that if I replace a part with a new one in search of a problem, that turns out not to be the cause, then at least that part will be good for many years. AKA as 'throwimg parts at it' ...

Title: Re: Lights gently Flicker at Idle
Post by: Benz280 on June 24, 2022, 12:12:09

Thanks everyone, although I did not see the fan belt as lose, I tightened it up a bit and problem resolved.
I am thinking of replacing the alternator given that its original, nothing ever goes bad at the right time .   

Title: Re: Lights gently Flicker at Idle
Post by: georgem on June 27, 2022, 06:20:21

Thanks Cees - not sure that is going to stop me waking up in the middle of the night though............. :-\