i left my lights on in my 300D for only 10 mins as i ran inside and now the battery barely turns over the engine. i did install some Euro's about a year ago, and since then have had some dead batteries, but never was able to time a certain incident down to only 10 mins. what is my plan of attack when searching for my short? i do remember that when i installed the Euro's the instructions were not right because the highs and lows were switched on once side and not completely working on the other. I played around with it and got it all right, but i guess must have someting wired wrong.

any suggestions?


btw, this is a 3 month old battery.

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Grey '91 350SDL 214k Dad's car
Beige '81 240D 4 Speed 254k SOLD
Blue '82 300D 225k SOLD
White '95 E300D 46k SOLD
Blue '87 190D 2.5 Turbo 315k SOLD
Brown '80 240D 4 Speed 716k SOLD
Beige '80 300D N/A 119k SOLD
Blue '85 300D Model 186k T-Boned

Doesn't sound to me like a short, more like a loose alternator belt or weak charging. What is the cold cranking amps of the battery and reserve capacity? I ask because you might have purchased the wrong type for a diesel.

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81 300CD (sold) 1972 280 SEL 4.5 (sold) 1966 250 S 4 spd (sold) 1974 450 SL (sold) 86 BMW 325ES (sold), 1973 280C (sold) 1988 300 SE.

i got the biggest battery at autozone (was stuck in their parking lot), and it was the only one that showed up in their system as working for my 300D. 850/1000 cranking amps, and 155 reverse capacity.

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Grey '91 350SDL 214k Dad's car
Beige '81 240D 4 Speed 254k SOLD
Blue '82 300D 225k SOLD
White '95 E300D 46k SOLD
Blue '87 190D 2.5 Turbo 315k SOLD
Brown '80 240D 4 Speed 716k SOLD
Beige '80 300D N/A 119k SOLD
Blue '85 300D Model 186k T-Boned

THATS IT! thanks. Check alternator belt tension. Should not be able to rotate pulley against normal rotation by hand if properly adjusted.

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81 300CD (sold) 1972 280 SEL 4.5 (sold) 1966 250 S 4 spd (sold) 1974 450 SL (sold) 86 BMW 325ES (sold), 1973 280C (sold) 1988 300 SE.

You need to check resistance I believe.

http://www.google.com/search?hl=en&safe=off&client=firefox-a&rls=com.ubuntu:en-USfficial&hs=vBs&sa=X&oi=spell&resnum=0&ct=result&cd=1&q=multimeter+101+finding+a+short&spell=1


I am betting its a short, especially if you had problems wiring it up. Were the lights modified at all?
How did you wire the day time running lights?

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http://superturbodiesel.com/images/sig.04.10.jpg
1995 E420 Schwarz
1995 E300 Weiss
#1987 300D Sturmmachine
#1991 300D Nearly Perfect
#1994 E320 Cabriolet
#1995 E320 Touring
#1985 300D Sedan
OBK #42

Mine wouldn't last 10 minutes with the lights on. Sears replaced the battery for free yesterday. It was two years old. It just wouldn't hold a charge any more. I was pretty hard on it this last year.

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Michael LaFleur

'05 E320 CDI - 86,000 miles
'86 300SDL - 360,000 miles
'85 300SD - 150,000 miles (sold)
'89 190D - 120,000 miles (sold)
'85 300SD - 317,000 miles (sold)
'98 ML320 - 270,000 miles (sold)
'75 300D - 170,000 miles (sold)
'83 Harley Davidson FLTC (Broken again) :-(
'61 Plymouth Valiant - 60k mikes
2004 Papillon (Oliver)
2005 Tzitzu (Griffon)
2009 Welsh Corgi (Buba)

Folks,

If the headlights had a short, or are drawing an excessive amount of current, you would be blowing fuses.......assuming that you have the proper fuses in place......

the following is for an 85 300D

Fuse #7......8 amp, white.........Headlight (RH High Beam)
Fuse #9......8 amp, white.........Headlight (LH High Beam) and Indicator
Fuse #11....16 amp, red...........Headlights (RH Low Beam and Fog Ligts)
Fuse #13....8 amp, white..........Headlight (LH Low Beam)

copied exactly as written in MB W123 Electrical Troubleshooting Manual

So, If you didn't connect those lights up directly without any fuse......then you should be having some fuse problems......if you have some sort of short!!

If it were me, I would get a voltmeter and check my Alternator's output...there are several threads relating to this......

I would also check my ground straps.....

I assume that you gave the parts store your old battery, in lieu of a core deposit......but I would have fully charged the battery, slowly, overnite....then tested it with my trusty Snap-On Resistance type Battery Load tester......

Luck to ya.....especially if you have custom improved on the factory MB headlight power distribution system.....

SB

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Diesels:
'85 300D, "Max, Blue Benz", 155K, 27.0 MPG
'84 190D 2.2, "Eva, Brown Benz", 142K, 40.2 MPG
'77 240D (parts car)
'67 Eicher ES 202 Tractor "Otto" (2cyl, Air Cooled, 30HP)
Gassers:
'94 Ford F-150, "Henry", 170K (300 Six) 17.5 MPG
'85 190E 2.3, 148K....Parts Car
'58 Dodge W300M Powerwagon (Flat Fenders) Less than 10 MPG

I agree. It would blow a fuse. Why do people still get a short and a battery draw confused? Headlights on for ten min. is a battery draw! Headlight quitting and finding a blown fuse is a short! A headlight not working and no power to it is an open! For some reason your battery did not have enough reserve in it to restart, so the battery's correct, right. so why was it weak? Check alternator output voltage as well as amperage and ck belt tension. Then report back with the test results so we can help. Be aware that all these tests are to be done with a fully recharged battery, not before!

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81 300CD (sold) 1972 280 SEL 4.5 (sold) 1966 250 S 4 spd (sold) 1974 450 SL (sold) 86 BMW 325ES (sold), 1973 280C (sold) 1988 300 SE.

Seconded, my money is on a weak alternator.

PS. you can get a multimeter @ harbour freight for $4.99

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Cheers,
Robert

Remember, maintenance free batteries need to charge differently.

If I am doing lots of city driving in the MBs, I always go for a cruise after to get it really charged up and to get the motor good and hot.

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I'm not a doctor, but I'll have a look.

'85 300SD 245k
'87 300SDL 251k
'90 300SEL 326k

Six others from BMW, GM, and Ford.

Liberty will not descend to a people; a people must raise themselves to liberty.[/IMG]

just as likely he had a poor connection on old battery and putting in the new battery miraculously fixed the alternator

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commercial fisherman diesel in my blood in my boats trucks and Dear old Dad has had me drivin them since i got my first license in 1968
1986 300 SDL 427654
1999 Chevy Crew Cab Dually 225423
1986 300 SDL 287000 Dad's
1987 190 Turbo 158000 Mom's (my inheritance)

I have pretty much the same issue on my 87 300D. My money is on my battery being just plain old. It is 10+ years old and is due to be replaced. For some silly reason I just can't seem to make myself get it done. Maybe it is the MB 3 point star on the battery. I just don't know. For now I'm keeping 100ft of 12 gauge extension cord and my 2/10-30/60 amp start assist/battery charger in my trunk.

I know, just replace it.

-Jim

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1995 S350D, Green with black leather interior.
Bought January 2008 w/ 233,xxx miles.
I did 22,000 miles during the first year of ownership.

Electricity is Magic!!!!

SB

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Diesels:
'85 300D, "Max, Blue Benz", 155K, 27.0 MPG
'84 190D 2.2, "Eva, Brown Benz", 142K, 40.2 MPG
'77 240D (parts car)
'67 Eicher ES 202 Tractor "Otto" (2cyl, Air Cooled, 30HP)
Gassers:
'94 Ford F-150, "Henry", 170K (300 Six) 17.5 MPG
'85 190E 2.3, 148K....Parts Car
'58 Dodge W300M Powerwagon (Flat Fenders) Less than 10 MPG

naw, it's not magic, it's just that when the wires are all crossed and crunched, the power gets all spilled out and stopped up and stuff...
John

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John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 190D 2.5Turbo
1987 190D 2.5-5SPEED!!!

1987 300TD
1987 300TD
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

You are correct in your statement Electricity is Magic, All electrical components run on smoke, because once you let the smoke out, they never work again

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