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Trying to improve electrical ground

Started by michaeld, 08 February 2006, 12:37 AM

michaeld

Hi,
I've got a 77 450 sel which I've really enjoyed since I bought it for $800 a few months back.  The one owner prior to me left all his records, and shows he took very good car of the car.  This is a great site to sing to the choir about how great these 116 cars are: driving is such a pleasant, relaxing experience as the big car hums solidly down the road. 
In any event, she's still an old car even if she was well maintained.  I'm a little concerned about her overall electrical system.  The ignition system seems great, but some of the peripherals (radio, power windows) seem to have "issues."  The radio will work fine for a while, then one day it just won't work.  Same with one of the rear windows.  Then one day everything seems fine again.
I suspect a poor ground might be causing the problem.  I intend to replace the window switch in question, and if necessary take the radio out enough to improve its ground.  But first I wanted to improve the car's overall ground by replacing the ground straps and re-locating the negative battery cable.  Currently the negative calbe connects to the sheet metal next to the headlights.  When I scouted out potential spots on the engine block, however, I simply could not find a good location.  If nobody has a better idea, I will locate the ground cable onto one of the alternator bolts.
I really wanted to connect the ground cable to the cast iron block, as I understand that that is the best place, but I'm going to need help finding a location.
Relocating the ground may do nothing to improve my system, and it might be the trick.  What do you think?

John Hubertz

I'd be a tad suspicous of the "quality" of the power coming through the central power circuit for your accessories.  It is the one that is hot only when the key is on. 

Have you removed and polished all your fuse tabs?  They are notorious, and most cars have dissimilar metal fuses that corrode and begin to heat.  It sounds to me like you may have a fuse or fuse connection that has become a resistor in the power circuit, probably the central circuit that feeds primary juice to both the radio and the power window RELAY, not the two fuses that feed the actual window motors.  Since it is both back windows it can't be a single-source problem, and they are independently fused right front/left rear and vice versa.  For a handy reference pull the fuse location description that someone just posted - a lot easier when working on the car....  What a wonderful piece of paper that is!  I printed it right away, and I should have typed one out myself a year ago. 

An all-vehicle ground problem would create flickering headlights and instrument lights on bumpy roads, odd variations in cranking rpm and usually, a flickering alternator light.  It is always a good idea to service the battery connections and the engine/chassis ground point, but I doubt it will help.

Polish your fuse tabs with a dremel tool and a soft wire tip, then replace the fuses with a "best" quality set sold on ebay.  I can't recall if they are OEM, but they are wonderful.  Be sensitive to the tension on each fuse.....  frequently they become loose from heat over the years and a needle nose pliers can be used to gently tighten the "pinch" of the two tabs against the fuse nose and tail.

The CD rom shop manual from M-B has a wonderful, easily enlarged schematic of power and ground points.
John Hubertz
"When the going gets weird, the weird turn pro."
(Hunter S. Thompson) 

1977 450SEL (Max Headroom)
[img width=68 height=73][url="http://i48.photobucket.com/albums/f248/fullhappyfish/max.jpg"]http://i48.photobucket.com/albums/f248/fullhappyfish/max.jpg[/url][/img]

michaeld

John,
Thank you much for the excellent advice.  I will take you up on it.  I actually bought one of those sets of fuses on ebay (they are OEM fuses that are upgraded from the problematic originals), but haven't installed them yet.  I also just purchased a nice 229 pc dremel tool kit, so it sounds like (for once!) I've got all the tools I need to do the job. 
I also came across the post that included the fuse description, and yeah, I intended to copy/paste that also.  I volunteered to send the guy who asked for the info a scanned copy of my fuse box sheet so he could have it if he wanted.
I agree that replacing all my battery grounds/ground straps probably isn't the answer after reading your post.  Actually, it is only one of the rear windows - not both - that come on intermittantly, but that probably doesn't change much of anything.  The full set of "electrical" symptoms I've noticed so far are 1) an intermittant noise that comes from my servo; 2) the radio has occasionally failed to work for a couple days, then works for a week, and so on; 3) same deal as the radio w/ my right rear window; 4) my sun roof acts like it's not too happy about closing.  1) and 4) have alternative explanations, but if changing a few fuses will help me w/ the radio and window, I'm on it.

Thanks again,
Mike

John Hubertz

Mike,

Be aware that if your car has not been maintained by a fanatic, the window regulators and tracks, and the sunroof mechanism must be lubricated immediately before use.

Very expensive not to.  And annoying.  And heartbreaking.

These motors are very low torque, and they are not clutched, but have breakaway components that are $$.  It is annoying to pull door panels, but it is very very annoying to realize that you just destroyed a perfectly functional half-moon window regulator by chewing off the teeth.

I don't know what breaks in the roof, but I know I don't want to pull a headliner.

Anyone know the proper procedure for lubricating sunroofs?
John Hubertz
"When the going gets weird, the weird turn pro."
(Hunter S. Thompson) 

1977 450SEL (Max Headroom)
[img width=68 height=73][url="http://i48.photobucket.com/albums/f248/fullhappyfish/max.jpg"]http://i48.photobucket.com/albums/f248/fullhappyfish/max.jpg[/url][/img]

John Hubertz

Styria!

I'm laughing and crying at your post - I just realized that I purchased my '77 without checking something.

Guess what - no sunroof!

Arrghh!

A three-button dashboard in a four-button world.  (Sob)

John
John Hubertz
"When the going gets weird, the weird turn pro."
(Hunter S. Thompson) 

1977 450SEL (Max Headroom)
[img width=68 height=73][url="http://i48.photobucket.com/albums/f248/fullhappyfish/max.jpg"]http://i48.photobucket.com/albums/f248/fullhappyfish/max.jpg[/url][/img]

michaeld

John and Styria,
Thanks for your posts.  I must confess to something: I have been a very bad boy.  I have not lubricated my electric motors.  I guess I'm used to newer cars where this isn't really  an issue that comes up.  One of the things I need to keep reminding myself is that some of the stuff on these cars was state of the art in olden days, but needs more maintenance than today's electronics.
In terms of specifics, do you have any sources that detail the maintenance process?  Maybe its in the manual that is indexed to this forum site?  I'd like to find out the procedure for taking the door liners apart before I do something I might regret.
I'm still trying to get my hands on a good manual.  I bought the chiltons, but it is woefully inadequate.  I bought a mercedes cd on ebay, but it was a homemade copy (avoid seller patamart).  So I'm back in the market.
I suppose another question is what to use as lubricant.  I'm not real likely to shell out a hundred bucks for a tube of goo, thank you!

The guy who owned the car before me was an M.D. who was pretty good about doing preventative maintenance.  He WOULD have spent a hundred bucks on a tube of goo.  I have receipts that show he paid $28,000 over the years in service!  I haven't checked the ratio, but a whopping chunk involved work on the climate control system.  Built to last those things weren't!  Still, having 28 years worth of records that show your car never missed an oil change is reassuring.  Also nice was that he spent $3500 on major maintenance which included a front end overhaul.  Part of why I enjoy this car so much is that it drives so "new."  Still, none of that means my window/sunroof motors got lubed... 

OzBenzHead

#6
Quote from: michaeld on 09 February 2006, 01:05 AMI'd like to find out the procedure for taking the door liners apart before I do something I might regret.
I'm still trying to get my hands on a good manual.   

Michael:

The manual available from this site is the way to go. Even though it is largely North American in orientation, it has proven invaluable to me and my mechanic.

Door liner removal is the simplest of almost any car I've owned. I'll describe the driver's door; the others are similar.

1. Locate and remove screws. You'll find these:

    (a) 2 holding the armrest (on the driver's door, 3 on the other, larger ones) (medium Phillipshead) - the 3rd being found under the chrome bezel at the top end of the armrest (the bezel easily prises off with small, flat screwdriver)

    (b) 1 hidden under the plastic shield in the door handle bezel (the plastic shield easily prises out with a very small, flat screwdriver)

    (c) 2 securing the C-shaped chrome bezel at the door catch (medium Phillipshead)

    (d) 1 very small Phillipshead, near the top of the opening edge (i.e. "handle and latch" edge), of the door frame; this secures the rearmost piece of window trim.

    (e) For those with manual window cranks, prise off the trim strip, and remove the Philliphead screw; lift off the handle.

    (f) For power windows (rear doors) remove switch with care from door trim.

2. Once you've unscrewed all those, remove - with whatever gentle persuasion required, but it won't be a lot - the armrest, door-handle bezel, door-latch bezel (probably came off with the screws), and window trim pieces (2).

3. Next, lift the bulky surrounding door-trim piece from the top (near window sill); this should free the trim of its slide-in clips at top and bottom edges (these are not the pop-in variety).
You should then be able to lift away the bulky surround trim piece.

4. To remove the remaining trim - the flat part - gently lift it out at the edges with your fingers to see where the pop-in clips are located. Place a flat device - something like a wooden ruler perhaps - behind the trim piece as close as possible to the clips, one at a time, and prise the clips out of the metalwork. As long as the "masonite" is sound (not too water-damaged), the clips should stay in the board as you remove it.

5. Then there remains just the weather-proofing sheet of plastic. As it's unlikely to survive, you'll need to replace it. I use a heavier grade of clear plastic, and I reseal it with non-silicone (important!) windscreen sealant.

That's it.

Have fun!
[img width=340 height=138][url="http://i12.photobucket.com/albums/a215/OzBenzHead/10%20M-B%20Miscellany/OBH_LOGO-2a-1.png"]http://i12.photobucket.com/albums/a215/OzBenzHead/10%20M-B%20Miscellany/OBH_LOGO-2a-1.png[/url][/img]

Denis

Hi John

The point is that at their age (25+ years old), it is desirable to re-lube the window assemblies.

I have removed these and found out that the lube in the motors was OK, I did replace it for good measure, I also checked and cleaned the motor brushes with alcohol. You don't really need to lubricate the window assembly motors.

The important and easy thing to do is remove the door panels and lubricate the teeth and mechanism axis points - WD40 to clean out things and then add some normal grease.  That should be enough if the motors work correctly. Do not try to remove the assemblies if you value your time. Doing all this is cheap and easy. Cleaning the window channels is important also. I have used silicon spray successfully. If the window does not move up and down smoothly, the mechanism may need adjustment (channels positioning) and this gets more complicated.

BTW, all this stuff was designed that way to prevent serious injury when kids got their hands stuck in there...at least D-B was thinking about this thirty-five years ago  :o

Denis

Paris, France

John Hubertz

Great description of door panel removal - thanks!  I know the W126 door panels are nightmarish and I wasn't looking forward to servicing my 116.

I've yet to use more then a squirt of WD40 at the motors themselves, concentrating on the channels and regulator pivots etc.  Be a bit stingy once you're above the lowest point the window travels....  a streak of lithium grease or silicone every time you cycle a window has been known to cause pulmonary embolisms.

Another thing -  It is hard to recognize just by looking, but modern automobile doors are "wet" assemblies -  everything inside the door itself is exposed to the elements, water running down between the glass and the wiper seal during rain or other inclement weather.  Humidity is the real enemy, as the cycling of warm interior air against the inner door surface and door panel routinely causes condensation on all the mechanisms and the metal itself.

While in the door, be sure you clean the bottom of the door (inside and out) with a damp cloth, then mist a petroleum-based product (WD40 is good, as it is designed to penetrate regardless of gravity into even the smallest crevice) into the door bottom.

Too much is better then too little but only below the lowest point the glass reaches as it travels. 

This will act both as a rust preventative and provide some protection to keep humidity from interacting with any exposed metal surface and then wicking into welds and seams. 
John Hubertz
"When the going gets weird, the weird turn pro."
(Hunter S. Thompson) 

1977 450SEL (Max Headroom)
[img width=68 height=73][url="http://i48.photobucket.com/albums/f248/fullhappyfish/max.jpg"]http://i48.photobucket.com/albums/f248/fullhappyfish/max.jpg[/url][/img]

OzBenzHead

Good advice there from John.

A formula I've used for decades, and found very effective as a rust preventative, especially in awkward-to-reach places (awkward for everything except water and humidity, that is!):

One third fish oil (the true blue, undiluted, undeodorised yukky stuff that won't, on its own, spray), one third thinning solvent such as  kerosene (beware of some other solvents - they aren't necessarily paint-friendly!), and one third diesel. The kero makes the mix sprayable. The diesel "wicks" upward into places you just can't see to be sure you've adequately sprayed into.

This does require care; do not get the mixture onto natural rubber. This often means removing some seals, but as it's not every day it needs doing, it's no big deal (to me). If inside doors, also a good idea to remove window channels.

Sure, it stinks for a couple of weeks - but is well worth it. (Just don't do all your cars at the same time or you'll be walking everywhere!)

One generous application every five years
(including inside sills and all double-skinned panels) has kept my cars 95% rust-free.  That includes the tailgates of some Ford station wagons!  What rust I have had has been external, where paint has been chipped.
[img width=340 height=138][url="http://i12.photobucket.com/albums/a215/OzBenzHead/10%20M-B%20Miscellany/OBH_LOGO-2a-1.png"]http://i12.photobucket.com/albums/a215/OzBenzHead/10%20M-B%20Miscellany/OBH_LOGO-2a-1.png[/url][/img]

michaeld

John, Denis, and Ozbenzhead,
You guys are too cool.  Thanks for the excellent how-to tips.  I will copy and print them out and start working on putting it all into action.
I really enjoy this car, and have decided that it is worth giving tlc to.  The first thing I'll do is swap out the fuses, and then I'll get to work on the doors and sunroof.  One of the first things I noticed when I drove the car was that the motors were 'old and busted' rather than 'young and hotness.'  If I can get them working at 100% w/o forking over big $, I am willing to open a can of elbow grease.
Fortunately, my car is a Southern California girl that has never been outside the state.  I hear that rust has been hard on these 116 cars in the midwestern and eastern USA (because of salting the roads?), but my car is pretty darn clean rust-wise.  Still, I'll get to work putting that "witches brew" together and put it on one section at a time.

By the way, ozbenz, do you know if there is any way to purchase a cd of the manual on this site?  It IS good, but I would sure like to have my own copy.

OzBenzHead

Quote from: michaeld on 10 February 2006, 07:17 AM
John, Denis, and Ozbenzhead,
You guys are too cool. 

Aw shucks!   :-[   You are getting truly international value here, you know: USA (John), France (Denis), Oz (Yours truly).  Ain't the internet just someting!

QuoteThanks for the excellent how-to tips.  I will copy and print them out and start working on putting it all into action.

That's what a good forum is all about: sharing our pooled understandings. It's called community - even if it is virtual, it's very real, too.

QuoteBy the way, ozbenz, do you know if there is any way to purchase a cd of the manual on this site?  It IS good, but I would sure like to have my own copy.

I have seen them for sale on eBay from time to time. Beware, though: some of them are poorly (home)-made copies and lack full functionality (or so I've read on various forums).  Perhaps worth checking with the M-B Classic Center nearest you (and then maybe finding somewhere less expensive to purchase one!).

Have fun!
[img width=340 height=138][url="http://i12.photobucket.com/albums/a215/OzBenzHead/10%20M-B%20Miscellany/OBH_LOGO-2a-1.png"]http://i12.photobucket.com/albums/a215/OzBenzHead/10%20M-B%20Miscellany/OBH_LOGO-2a-1.png[/url][/img]

John Hubertz

I've got the cheapie ebay copy and all you need to do to get it to work perfectly is:

1.  Restore your internet explorer default settings, especially security and advanced internet

2.  Whenever it calls for an internet explorer address that ends in .pdf, you must MANUALLY hit the "go" button on the address bar at the top of your computer.

3.  You'll quickly realize that the page numbers are in the address, and you can jump from page to page as if it were paper.

Plus, the online manual on the front page of this site is the same manual!

John
John Hubertz
"When the going gets weird, the weird turn pro."
(Hunter S. Thompson) 

1977 450SEL (Max Headroom)
[img width=68 height=73][url="http://i48.photobucket.com/albums/f248/fullhappyfish/max.jpg"]http://i48.photobucket.com/albums/f248/fullhappyfish/max.jpg[/url][/img]

michaeld

John and Ozbenzhead,
Thanks for that last on the cd manual, John.  I'll give it a try tomorrow.  If it works, YEAH!!!
As for Ozbenzhead's comment, it's really true.  This is a communtity of folks who have a common love (even if love-hate sometimes) of MB 116 cars.  After about thirty years on the road, these cars all have their own characters, don't they?  And we to varying degrees have fallen in love with these cars, and wonder - maybe too often to be truly sane - "what can I do to make my Benz happier?"
Anyway, when I first joined a MB forum, I was kind of in it for myself, and once I got the info I wanted, I was gone.  But after a couple of knowledgable people shared their know-how with me, I started to want to be at least a little bit like those guys and pass the scraps I'd begun learning around to others.  Even if I never see any of y'all, it's truly nice to have you as a resource, and to be able to chip in and provide useful info to someone else about something you've learned about.  And I know that if we actually DID see each other on the road, we'd stop, and ooh and awe over each others cars.
Mike

Denis

Hi michaeld et al  ;D

The CD : is have the original US CD and you must have it just to see that new icon gold S-class drive up and past you  in the intro  :)

Community : in a very real sense, people here help each other as they feel amongst friends : anyone that likes a W116 cant be all bad  :o

Seriously, helping people here is world citizenship at its best level. Besides, I really need to go to Oz some day to see styria's gas milleage down those long flat aussie straights...

Regards to all


Denis

Paris, France