Alternator story
 

Yesterday I noticed my battery light started illuminating at low RPM, at high RPM there would be no light.. I figured OK, time for a new alternator soon. I drove it like that for about 120 miles last night.

Today I had to head into Brooklyn, NY and while on the Verazzano (sp?) bridge, I noticed that my windsheild wipers were a little slow, my heater fan went to a whisper and my radar detector started resetting.. I knew I was in trouble.

It was a snowy, icy day here and you really need your wipers, especially with the road salt that smears the windsheild. I get to my destination and don't dare to turn the car off. As time went by, sure enough the battery was draining. My "antilock" light came on (comes on when voltage is under ~12.5), and my cluster started acting funny. The car also started idiling strangely.. newfangled 603 engine.

I head home and my wipers quit.. I had to keep stopping and wiping the windsheild with napkins to be able to see.. but the engine still keep chugging along. When I got home I started preparing everything to just pull the SDL up on ramps in such a way where another car could jump start it when I was done.. first I had clean all the snow off the other cars. I put her up on ramps, shut her off and sure enough the battery was completely dead.. not a peep. I run to my local MB dealer and pick up an OE alternator for a cool $245 plus core and taxes.. over $300 by the time I walked out. Put it in and she fires right up without hesitation.. took about 2 hours.

I did just notice that there seems to be an extremely tight tension on the alternator pulley, it almost looks as if the pulley is cocked a bit under the tension and the alterantor is squeeking very faintly.. any ideas? I had a heck of a time getting the belt back on with the tensioner completely off.

Anyway, I just wanted to share, I think I love this car more and more as each day passes as it continues to impress me.

john, glad it did not strand you yesterday! just curious about the old alternator though, was it totalled? could you not have replaced only the voltage regulator/brush assembly to get it working again?

2 hours?
 

I had the same low level battery light at low rpm's and nothing at high rpm's and the light slightly brighter after I turned the lights off at night. Checked the battery and the ground with no change.
Decided from looking at the alternator that I would take the one off the parts car, have it completely rebuilt and then the "driver" car would not be down as long.
Well the weather has been bad, business has been good and one thing leads to another and I'm still driving with the battery light on slightly when idling over a month (maybe two) after the light first coming on.
Is it possible that is not the problem?
You mentioned 2 hours to replace your alternator. On this 115 240d I have to remove the ac unit to get the alt out and remove the fan and shroud to get to the ac unit and the water pump falls off when you remove the bolts for the ac bracket. I ran out of daylight yesterday so I am not sure what else I will run into.
Is your car alot different from mine or am I doing this the hard way?:rolleyes:

Thanks

TD:

I had the identical struggle to get the belt back on the pulley.

I would echo a former post about the voltage regulator in the back of the alt. However, by the end, I had to replace both.

Don

This is another example of the beauty of the 60x engines. The alternator job is about 1.5 to 2 hours on a 123. I hesitate to guess what the replacement is on a 115.

I have replaced the alternator on a 60x in about 45 minutes. After loosening the tensioner spring on the serp belt, there are two bolts that hold the alternator in place. Once you remove these, you can make a quick job of disconnecting the single connection and the rear cover. 45 minutes is the time it takes if you stop and clean everything along the way. It is probably closer to about 30 minutes if you are in a hurry.

I replaced the 60x alternator in my office parking lot, due to the ease of same. The rebuilder was near my office so I took a couple of tools with me.

All of the 61x alternators that I have replaced have been replaced at home in the garage. The require more work.

It is very possible it needed just a regulator, but I remember one time I spent all this time getting a regulator and putting it in and it still didn't work. I needed the car to be on the road ASAP so I didn't feel like playing around with it. The alternator was also noisy, so even if it did just need a regulator the bearings were on the way out.

Curiously, your replacement comes at 308k,

My first replacement was at 305k.

I believe that it is the same alternator.

Interesting.

I really think this alternator may be original. I know the regulator was replaced once, but the sticker on the alternator says "BOSCH" and nothing about being rebuilt.

Taking the alternator out and putting it in was very easy, the only mildly difficult part was getting the pulley and fan assembly off the old alternator.. it is on very tight.

http://www.onlineautolink.com/300sdl/alternator.jpg