Hi everyone,
So the alternator failed in my W124, (I know its the alternator b.c I took it to an electromechanic who strapped it to one of those bench testers).
Anyhoo, they had an alternator in stock available by Gamma Electronics. Fit the car perfectly, so I went for it. Upon installation, we discovered the connector was not the same as OEM, in fact it was very different. It had a bolt connector for the + terminals and a mini connector for the bat charge light in the dash. Basically the mechanic told me he would connect the two large cables from the cars harness together, solder them, and strap them to the bolt via a clamp connector, and the little wire was solderd to the mini connector.
The alternator IS charging the car properly now, however all the dash lights on the left side do not light up. The batt light illuminates VERY dimly (you have to squint to see it) when key is in pos 1, but goes out when the engine is on.
So what do I do to get the dash lights functioning again... did we cross wires stupidly? Is this type of connection bad for the W124?

It has something to do with the alt or the wires. If I were you i'd undo what ever he did and put the correct alternator in the car.

__________________
1985 300TD Turbo Euro-wagon
1979 280CE 225,200 miles
1985 300D Turbo 264,000 miles
1976 240D 190,000 miles
1979 300TD 220,000

GONE but not forgotten
1976 300D 195,300 miles
1983 300D Turbo 175,000 miles

http://i42.photobucket.com/albums/e3...e485-1-2-1.jpg

The setup the "Wrench Turner" enacted for the wiring connection difference
is almost exactly what GSXR did to be able to "UpGrade" his W124 to a 150 Amp
setup. [Dave used larger AWG wiring for the 150A](See Picture below)

I've gotta "Prognosticate" in reverse (Hindsight) and speculate that "Someone"
either left some connections "Off" or LOOSE (SOMEWHERE?)maybe,behind the dash panel during the modifications...
OR OVER Voltaged/Amped that side of the Panel Whilst "Non-Georgia Tech
Approved Re-Engineering"ed the electrical system.
(When the "Wrench Turner" "Soldered" the "Little" wire to the "Mini-Connector",
DID he disconnect the opposite end of the little wire FIRST?)
(Did he "Solder" it with an Arc Welder, Maybe?)


Hint,Hint,Hint...

The Grounds behind the IC are notorious for screwing with us!

EDIT: I just saw 79mercy's reply AND it does have it's merits!

Attached Thumbnails

   

__________________
'84 300SD sold
124.128

Ok, I didnt follow everything you said, so lets go down the list
Behind the dash pannel = I dont recall anyone going down that area at all... all we did was pull the alt out and put the new one in. No work done near the firewall or rear of the engine.
Connector loose = possible, perhaps near the battery? Where should I check?
Over Voltaged = Really didn't follow you on that one... can you explain it in more layman terms
Soldering little wire = I dont think he disconnected it from the opposite end, at least I didnt see it. He used a generic electrical soldering gun for the little wire, and a bunson burner for the large gauge wires. (bunson burning was done with all wires disconnected from car.
Ground behind IP = What is this IP you speak of?

IC is as above.

#1 were ALL your IC lights AND the Battery Light functioning correctly BEFORE
the modifications?

(EDITED for Common Sense)
If all was O.K. before the Mechanic worked on the vehicle,the "Monkey's
On His Back" to figure out what he did that changed things.When I pay
someone to fix something,I don't accept it back with something new
wrong/broken.

If so,either something was damaged,or misconnected,or as 79mercy implies the
Unknown quantity of the replacement alternator may be the problem.

I do not recognize the brand of Alternator sold you by your mechanic.
I have found (With a LOT of help from much more knowledgeable,professionals)
that you have to be very,very careful reverse engineering Mercedes.
I have a 143 Amp alternator upgrade...
BUT only after following GSXR's excellent postings of ALL the necessary hoops to be jumped through.

Thank You, dealwithit for pointing out the error of my abbreviations.

__________________
'84 300SD sold
124.128

IP = injector pump

__________________
93 b2200 EFI turbo, reg cab/short box, F2t swap build thread here
92 B2600i Cab plus getting a 82 3.0L 5cyl 617 mercedes Turbo Diesel build thread here
96 GMC 1500 z71 4x4 6.5L turbo diesel
Diesel all the way!!!

If this mechanic has a bench tester for the alternator he also should have a load tester for when the alternator is in the car. That simple test with a load tester will tell you everything...

__________________
83 300CDTurbo 307,000
2005 Honda Element 266,000
56 Nash Ambassador Country Club Special 34,000(under restoration presently)

http://www.peachparts.com/shopforum/car-audio-multimedia/125099-123-install-extreme-dynamat.html

Were there three terminals on the alternator? Normally yes, and it sounds like the small lead was hooked to the wrong one.

__________________

Gone to the dark side

- Jeff

Thanks for all the input guys.
Im going to take the car back to the elctromechanic tomorrow and have them take a look at it. It is possible that the small wire is hooked up to the wrong wire from the connector. There are indeed 3 wires from that connector, so it is possible.
Ill keep you all posted.

I hope that they didn't solder the wire to the little connector on the alternator, ... if they did, run away.

__________________

Gone to the dark side

- Jeff