Electrical problem with '89 124 Series 260E ?

[srobertson]

While driving on the motorway at the weekend the first sign of a problem was that the ABS light illuminated.

Over the course of the next 20 miles various other symptoms appeared - the radio lost reception, the dash lights dimmed, all external lights dimmed, the oil light flickered on occasionally, indicators no longer made a clicking sound, and eventually the engine started to misfire.

Attempting to restart the car, the battery appears to be flat.

I'm guessing the alternator is at fault ?

If so how big a job is this for a 1989 124 series 260E ? Anything I can check ?

Where is best to source a replacement - Eurocarparts and GermanSwedish are both approx £120+VAT ?

Thanks

 

[Griffo]

I had more or less the same experience Friday night. Noticed wipers were slow and lights dim, made for home. SRS and ABS lights came on but NOT the Charge Indicator Light - STRANGE??

Put a spare, charged battery on the car, reset the immobiliser and she started up fine. Went to a local garage, who tested the battery with a voltmeter (whilst engine running, of course) and declared the battery wasn't charging. They reckon it's the alternator (£200+ for my '95 E280!).

However, looking in my Owners' Manual it says that if the Charge Indicator Light doesn't come on when the ignition key is turned to position 2 or doesn't go out when the engine is started, there is a problem that needs a MB dealer to fix. I understand that if the light comes on and stays on when running, there is a charging problem, so either a duff battery or alternator, I guess. BUT if the light doesn't come on when the key is in position 2 prior to starting, can the systems detect an alternator fault when it isn't even running? Or could this mean that some other component is faulty??

 

[paulcallender]

.....if the light doesn't come on when the key is in position 2 prior to starting, ......could this mean that some other component is faulty??

The bulb????

 

[smee]

The bulb????

yes or the wireing 2, it it needs the charge light 2 exite the alternator. on the rear of the alternator ull have 2 wires one large and one smaller the large one is ur main battery feed, the smaller 1 is the charge light remove the smaller one and earth it 2 the body of the car if the light comes on ur alt is faulty if not remove the clocks and check the bulb if its a bosch alternator its probably just the regulator which can be replaced cheaply (just 2 screws on the rear of the unit) think they retail at 20>27

 

[srobertson]

Yes I forgot to mention this important point - the Charge Indicator light did not illuminate at all when the problem occurred, so it sounds as if we have both experienced the same fault.

I did check the bulb using the ignition switch and all the dash light illuminate ok.

Wood Auto Supplies appear to provide a range of spares such as brushes and regulators etc to repair the alternator unit http://www.woodauto.com.

The main dealer here wanted £303 for a genuine MB part and taking my old unit in exchange !

Just need to check if the alternator in my 260E is a Bosche unit.

 

[Griffo]

I haven't checked my dashboard charge indicator bulb but wouldn't mind betting it's OK. See the threads by djlew (Electrical problem 300SL) and Mountainman 40 (car came to a standstill 300SE) below. These sound the same, so I've asked them to give some more details of their experiences. It would seem there's a chance that the alternator may not be shot but just need new brushes/whatever. Maybe clasping at straws but worth a try?

Thanks for the responses folks.

 

[smee]

The bosch alternator is a good unit 2 repair usually most of the time ull get away with a reg the brushes are part of the reg, and if u can get 2 the back of the unit 2 undo the 2 screws ull save the labour of taking it off aswell as the price of the unit.

the unit is very easily tested with even the most basic multimeter.

 

[gavmcc@aol.com]

260e Electrics failing

This sounds like alternator trouble and the battery is not charging. However, don't be thinking it's the whole gubbins that needs replacing. It's normally the regulator brushes that have worn out. These are contacts that become shorter and shorter with friction, evenually making no contact with the spinning part. It's is the component on the lower side of the alternator with wires sticking out of it. It's normally fixed on with a couple of phillips screws. (easy to carefully remove) The replacement costs about £15 or less from your Merc dealer. Have vin ready when calling, also alternator make and number to be sure it's the correct model.

Dealers always opt for the expensive "rep£ace a£ternator" choice. There is a time when this will have to be done, but try the cheapo first.

Gavin

 

[srobertson]

Just a follow up to say that changing out the regulator/brushes module did the trick.

One of the brushes was almost entirely worn away, so after a bit of fiddling to remove the two bolts holding the module in place, managed to get it swapped out for a new module.

Due to the location of the alternator I wasn't able to check the condition of the slip rings (to do so would have involved removing the alternator unit) but everything looks good for the time being.

Thanks to all who made suggestions.

Stuart