Hi all
I just put a new alternator, battery, shock tensioner, drive belt on my 1992 om602 w124
After it was all back together got it running with the old battery still in and noticed that the battery light and abs light was still on after it was running for a bit, so I put in my brand new battery I had, battery light was still on. Took the car to autozone for an battery alternator check , the auto zone guy said my battery was a little low so he put it on the charger for about 3o minutes, reinstalled the battery started it up. Battery light still was on the dash, so I drove it around a bit when I floored it the battery light went out along with the abs light which had also been on. Fast forward to last night battery is dead as a door nail. I also noticed that none of my idiot lights come on when I turn the key. When the car was running and I put a multi meter to the battery it was only 11.6 volts with the car running with head lights and fan it was down to 10 volts. What could it be? Ground strap on the bottom of the engine? Bad voltage regulator in a new alternator ? Relay? Iam at my wits end
Thank you
Ken Willmann

Take the alternator back to wherever it came from and have them give you a good one.

X2 ∆∆∆ and have them test the new one before installing it.

Good luck!!!

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"Rudeness is a weak man's imitation of strength" - Eric Hoffer

Thanks for the reply’s so would that explain the idiot lights not coming on when I turn the key?

Idiot lights ground through the alternator when the key is on but engine stopped. If the "new" alternator is garbage, they won't work. "New" doesn't always mean "Good".

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Current stable:
1995 E320 149K (Nancy)
1983 500SL 120K (SLoL)

Black Sheep:
1985 524TD 167K (TotalDumpster™)

Gone but not forgotten:
1986 300SDL (RIP)
1991 350SD
1991 560SEL
1990 560SEL
1986 500SEL Euro (Rusted to nothing at 47K!)

Thanks diesel300
The idiot lights worked when I first installed the alternator but all went off when I drove the car and floored it to get on the hi-way then they all went out

So I just called Napa and they said there are two different alternators for this car, a velo and a Bosch one, and that they were different sizes anyone heard of this?

Depending on the psec of the car a/c ect it may have a 96 amp or 115 amp fitted to later cars, also some had clutches which would also be a different part number.

Mine was a 96 amp but upgraded to 115 amp as both same size physically. It also worth a mention is rebuilding yourself if happy do to do, kits include both bearings brushed and copper actuator for around $30 or so - tolls needed, punch driver to get screws out and small puller to remove pulley.

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David


1996 Mercedes S124 E300TD - 129k - rolling restoration project -

1998 Mercedes W210 300TD - 118k (assimilated into above vehicle)

Well just pulled alternator off took it o Reilly’s and had it bench tested it’s no good failed all three tests and the pulley squeaked when turned. Guy at the counter said I had to pay shipping to get another one? WTF?

O'Reilly's Customer Service 888-327-7153

Sometimes their rebuilders have a bad run of parts. They figure on at least of few failures in order to get the best margin of return.

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Sam

84 300SD 350K+ miles ( Blue Belle )

The instant they told you this you needed to as for the manager, they're refusing to honor the warranty ~ they get parts deliveries daily, no charge, ever for bringing parts in .

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-Nate
1982 240D 408,XXX miles
Ignorance is the mother of suspicion and fear is the father

I did then what I knew how to do ~ now that I know better I do better

Remember to get the replacement bench tested before installation.

Good luck!!!

__________________
"Rudeness is a weak man's imitation of strength" - Eric Hoffer

Hi all
So it was a bad alternator from Napa, got the new one on and all is well.

Don't feel bad. The same thing happened to me 2 weeks ago from Napa on a 240d. Got one of there house branded rebuilt units. When it came in, I immediately called out the generic voltage regulator, that I've never seen before. Everything just felt poorly done about the whole thing.

Anyway, against my better judgement I installed it. After 15 miles it wouldn't charge at anything over idle. Thought it was the reg. So I called, to see if they could warranty / swap one with me. They wouldn't, and it would cost 25$ but I had to pay 15$ to ship it to them.... That last part didn't make me feel any better about the whole thing....

So I got a hella reg. from the interwebs. Still had the same issue(diodes shorting out?). So off the Alt came.

After a long chat, I went with the Bosch rebuilt unit. It came, and all was well.

Now I could have got another 10 cheaper Alts, and all might have been fine.

Felt kinda helpless with it broken like that, not to mention the lack of warranty coverage..

Same thing happened with a "rebuilt" carquest starter for 240d didn't even make one turn..... They returned it with no issue, and apologized numerous times..

These situations are why I prefer to use my local rebuilder. He rebuilds the item you bring in and is there if a problem arises.

I realize not everyone has this luxury but fortunately I do and it has served well.

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"Rudeness is a weak man's imitation of strength" - Eric Hoffer