[W126 Coupe] Strange electrical behavior questions

[Josh Allen]

The car I am having the issues with is an 84 500SEC.  The parts car is 
an 80 or 81 300SD, and the other driver is an 82 300SD.  I also have a 
push button unit from a 380 SE, of unknown year.

Regarding the fuses again:  I removed a functioning fuse.  I replaced it 
just because I had new fuses, but the new one was junk, and melted the 
body, not the metal strip.  Once I found the problem, and replaced it 
with the old ceramic body fuse, it worked fine, up until it decided to 
not run the high fan settings.

There is already a 30 amp fuse fitted in a holder just forward of the 
fuse box, on the wheel well, but it has been cracked through the whole 
time I've had the car, so I'm not sure just what it is supposed to be doing.

-Josh

Markus Meyer wrote:

> What year is your car?  Word of caution - the pbu's are NOT compatible 

> across the years, I found this out recently!  They seem to be backward 

> compatible (you can use newer years in an older car) but not the other 

> way around....

>  

> Markus Meyer

> mfm at meyerprobateproperties.com <mailto:mfm at meyerprobateproperties.com>

> www.meyerprobateproperties.com <http://www.meyerprobateproperties.com>

> Meyer Probate & Properties, LLC

>

> 484-919-9762

>

>     -------- Original Message --------

>     Subject: Re: [W126 Coupe] Strange electrical behavior questions

>     From: Josh Allen <heyallen at null-ptr.net>

>     Date: Fri, August 22, 2008 3:40 pm

>     To: Mercedes Coupes Mailing Lists <mbcoupes at mbcoupes.com>

>

>     Markus and Mr. McGoo,

>

>     I'll take a look at the push button unit, I have two (or even

>     three, if

>     I consider the one in my other car) nearby to play with.

>

>     As far as the fuses go, it appears that the only reason I melted

>     the one

>     fuse body was due to it being an exceptionally poorly formed

>     conductor

>     on the BUSS fuse I purchased from Schucks.

>     Before I replaced the fuses just because, I had had no problems. The

>     new, junk, fuses metal bits were not formed evenly, and looked

>     more like

>     they were folded over the ends, with a small attempt at putting a

>     dimple

>     in them, rather than the conical end that the old fuses had, and that

>     the new ones have as well.

>     No problem there, as I replaced it with one of the older fuses,

>     and then

>     ordered a set of ceramic and copper GBC fuses off of one of the

>     vendors

>     who stock them.

>     Once I had removed the Schucks fuse (with the partially melted

>     body), I

>     got the fan function back, until this latest odd behavior started.

>     While it was melted, I had no fan at all.

>

>     Regarding the high beams, I've checked the bulbs, and the wiring from

>     the fuse box forward, by jumpering from the low beam power to the

>     high

>     beam power. The high beams lit, they just won't when selected

>     internally.

>

>     On the rear window defroster, mine flashes bright, but doesn't

>     stay on,

>     so I suppose I'll have to see what else is wrong with that system.

>     Somewhere along the line, at least!

>

>     Thanks for the suggestions all,

>     -Josh

>

>     Markus Meyer wrote:

>     > Josh,

>     >

>     > As these cars get older the solder joints in the pushbutton unit

>     can

>     > cause strange issues, assuming all else is well. Might be worth

>     > swapping out with a known good one to test that theory.

>     >

>     > The euro wipers/sprayers on the lights are supposed to work with

>     the

>     > lights on, windshield wipers working.

>     >

>     > You mentioned replacing the fuse once, then again and found it

>     > "melted". That would be worth keeping an eye on. First thing I'd do

>     > is change ALL fuses to the newer ones as they are old by now if

>     > original and can often cure electrical gremlins. Cheap to do

>     even if

>     > it doesn't change a thing (about $10 for all fuses).

>     >

>     > Markus Meyer

>     > mfm at meyerprobateproperties.com

>     <mailto:mfm at meyerprobateproperties.com

>     <http://email.secureserver.net/pcompose.php#Compose>>

>     > www.meyerprobateproperties.com

>     <http://www.meyerprobateproperties.com>

>     <http://www.meyerprobateproperties.com>

>     > Meyer Probate & Properties, LLC

>     >

>     > 484-919-9762

>     >

>     > -------- Original Message --------

>     > Subject: Re: [W126 Coupe] Strange electrical behavior questions

>     > From: Josh Allen <heyallen at null-ptr.net>

>     > Date: Fri, August 22, 2008 4:14 am

>     > To: Mercedes Coupes Mailing Lists <mbcoupes at mbcoupes.com>

>     >

>     > Josh Allen wrote:

>     > >

>     > > 4th:

>     > > How is the defroster supposed to work? I can select it, and it

>     > > momentarily gets brighter on the upper position, but nothing

>     > seems to

>     > > say that it's working, and it doesn't seem to defrost anything.

>     > >

>     > Err, I mean to ask about the rear window defroster. The front

>     one I'm

>     > fairly sure I understand. (It just wants to play with my hed

>     > currently. :)

>     >

>     > -Josh

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>     >

>     >

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