Saturday, August 28, 2010

Looking Backward...

So one of the many cosmetic issue this 500sl faces was a deteriorated rear view mirror. The housing had fallen off of the glass, and just the glass and some foam were suspended from the headliner.

Here's a pic of what it looked like from the outside...

Here's a pic of what it looked like from the inside...

So after doing some research and realizing that this mirror cost over $850 new from Mercedes, and used versions were selling for between $200-$300 on ebay and from the parts "recyclers" I decided to try to fabricate a more cost effective solution. 

I realized that GM cars (and most domestics) simply attach the rear view mirror to the windshield using a steel foot attached with a 2 part cyranoacrillate adhesive. The mirror just slides over this foot and is tightened down with a set screw. So I set off to find a compatible mirror, and ended up with a 10" GM mirror. Using my wholesale parts connections it cost me 13.99 for the mirror and 4.38 for the adhesive. - Using the permatex stuff specifically designed for attaching rear view mirrors to windsheilds.

The next step was how to make this look as if it had come from the factory. Once you pop the rear view mirror housing out of the headliner, and disconnect the electrical connector, you will see that there is a large portion of the headliner missing from the center section of the headliner with it out. You will see that the original rear view mirror "Arm" which holds the mirror to the bracket that attaches it to the headliner is held on with a 19mm nut. Using an open ended 19mm wrench, turn the nut a couple of turns and then you are able to remove it by hand. You will quickly realize that you have to cut the electrical connector off of the mirror side to get the mirror off. Once you do all that remove the nut, and several washers which hold the mirror in place. 
When you get the mirror off you realize you have about a 3/4" diameter hole in the housing where the original mirror arm came down from off the headliner. What I did was simply make a cheap plastic plug out of a bottle top, sliced with a razor blade, and held in from behind with a piece of gorilla tape. (all easily reversible). You have to put this plug between the metal bracket piece and the outer plastic shell of the mirror bracket. It will be obvious if you attempt it. Once the plug was in place I proceeded to snap the mirror bracket back into the headliner, without the mirror. Here is a picture of what it looks like from underneath. Mind you, that with the new mirror in place, you have to look from almost directly underneath to see the actual plug in question. 

Now it's time to attach the GM Mirror to the windshield. First thing to do is determine the position of the mirror. You only get ONE shot at attaching the little foot to the glass - AND the glue sets remarkably quickly, you do not have time to reposition it or change your mind, once its on, you're going to have to soak it in acetone and use a razor blade to remove the foot very carefully in order to not break the windsheild, and especially on a 500sl you do NOT want to do that.

That having been said, what I did was take the mirror and hold it in place where I wanted it to sit. Leave the foot on it, and mark the windsheild - i used a wax pencil, so you have a location for the foot. Once you are SURE that that is where you want the mirror - mind you there is some adjustment in the mirror so you can always readjust it as needed, take the set screw out of the mirror and remove the little metal foot, that is what you are going to be gluing to the windshield. Make sure you note the orientation of the beveled edge, because that is the only way the mirror will then slide on.

Take a razor blade and scrape the windshield at the spot you are going to glue it. Open up your glue package and the first stage of the glue is in the form of a little wipe. wipe it on the windshield and on the correct side of the little metal mount. Allow it to dry (the catalyst is suspended in alcohol so it dries quickly). Once it is dry open the tube of glue and put a couple drops on the metal foot, do not soak it, a little goes a long way here.

Then it's time for the moment of truth touch the metal foot to the windshield. Like i said you have basically a couple seconds if that of working time here. If you need to reposition make it FAST. You will feel the glue react and the foot become immobile. Sit there and apply pressure for a couple of minutes then let go. Now go get your favorite beverage of choice, and take a break because you have to let the adhesive cure for a while before you can actually attach the mirror to it. The instructions said at least 15 mins, but I waited an hour.

This is what the foot will look like attached to the glass:

And this is what it will look like from the outside. This will also give you a relative idea of the positioning I selected.

Once the glue has cured, it's time to attach the new mirror to the foot. Slide it over, and tighten the set screw.
Here are pictures of the final result. I don't think anyone would question it's presence in the car, unless they were an MB Purist, or performed a through inspection of the headliner underneath the mirror.

Thursday, August 26, 2010

Diagnosing the Convertible top issue

So as I mentioned before, initially when I got the car, the soft top refused to go up past 1/2 way. It would stop and you would hear a mechanical "click" It would go back down electrically. If you turned off the key, the top released hydraulic pressure and was then able to be raised manually. If you had the top sitting on the front latches, and then pressed the close button it would latch in the front and the rear section would fold down and latch electrically as well.

When trying to open the top, the rear section would fold up however the front latches would not release electrically. If you released the latches manually with a 6mm allen key, and then attempted to open the top electrically, the rear section would still come up, then you would have to turn off the key and manually fold the top back. Then turn the key back on and use the convertible top switch to close the top cover.

After doing some research into the issue, I came across a Mercedes Benz document for diagnosing the soft top. It stated that in the closing mode, the top not going past 90 degrees was caused by one of the two window down limit switches not closing. The car uses window down limit switches to determine that the windows are in the all the way down position. Only once the soft top controller has a signal from both doors that the windows are completely down does the soft top fold over the center section of the roof. Apparently the windows or the top can be damaged if the top moves with the windows up.

Armed with this information I tore into both doors (that was foolish of me as the wires can actually be tested at the soft top controller itself - more on that later). The window limit switches are clearly visible at the bottom of the door, almost in the center of the door. You will also see a little metal bar with a rubber cap on it attached to the center of the window regulator with a 10mm nut. This is designed to contact and close the window down limit switch when the window is all the way down in the door. Each window limit down switch has a plunger that can unclip from the mechanical switch. You will have to peel back the wiring loom with a razor blade to get to the actual wires. Each switch has two wires, a brown wire which is the wire that supplies ground to the switch, and a gray wire which leads back to the soft top controller.

The brown wires should show continuity to ground at all times, and the gray wire should show continuity to both ground and the brown wire when the switch is engaged. You may have to unclip a portion of the switch to be able to access the wire. In my particular case, the problem was the brown wire in the driver's door had somehow become disconnected from ground.

After tracing the wire back to its source I found it had been disconnected from the driver door and was not providing a ground source to the switch. After repairing that connection, I started the car, and hit the top close button and hoped for the best. And the top went up, I was waiting for the click but instead the roof folded over the seats, and voila it latched in the front. For some reason it seems like you have to let go of the button, and press it again for the rear section of the top to latch. The top opens fine as well, and all seems to be working now. Now onto upholstery repairs...

Here are some pics of the car with the soft top up.

Wednesday, August 25, 2010

Open Air Motoring - Soft top operation problems..

So me and a buddy got the hard top off with no issues. It unlatched perfectly fine.

Then I go to put the soft top up. The cover opens, the tops starts to come up, and stops with the roof exactly perpandicular to the body. You hear a mechanical click when the roof stops... It will go back down and tuck under the cover fine... But wont get past the 1/2 way point....

The rollbar operates perfectly fine up and down.

Time to do some searching on that.

I took the car for the first couple drives with the convertible top open, and even in the state the car is in now, it's still a wonderful experience.

A more thorough review - Electrical Quirks / Cosmetics

Electrical quirks:

The car has had an aftermarket stereo at some point, probably in the mid to late 90's but something isn't right there.

It has some high end components. Specifically a Nakamichi MB-100 6 disc in dash cd changer, and a soundstream rubicon amplifier in the trunk, but it isn't connected properly. The radio is connected to constant power, and will stay on unless you remove the detachable faceplate, regardless of if the ignition is on or not.

Secondly the drivers speaker makes some sort of intermittent thumping sound. I do not know if they are aftermarket or not. That may need a going over - and possibly a swap to a more modern aftermarket radio. Mp3 / ipod capability would be nice.

Lastly - the power locks ONLY operate from the trunk lock cylinder. All door handles flash red or green to indicate status, and the doors do actually lock and unlock. BUT it will only lock / unlock from the trunk lock. The key will turn the door lock cylinders, but it will not actuate the locks from the doors. Any ideas here?? I haven't tried the keyless entry because a couple of the 357 batteries are missing from the remote key. Do these keys need programming, or should just putting batteries in it do the trick??

Exterior cosmetics:

The car is in remarkably good shape exterior wise, although the paint seems a bit dull and has contaminants on it at the moment. It's obvious it sat outside for a while. A good wash / wax and then we'll see, it may need some machine polish work.

Were 1990 R129's basecoat / clearcoat or single stage?

Headlight doors I guess they are called... The frames around the headlights, show their age and have gotten cloudy and faded. The passenger side has a crack / chip in it that looks like it got friendly with a rock.

I know this seems like a long list, but really the car isn't that bad.. I'm very particular and described every flaw that I could possibly come up with.

Day One - Bringing the 500SL Home

So I found this original 73,000 mile 1990 500sl through a friend. The car had been in the family since day one and a decent history, however it had sat neglected and unused.

First the car is a 1990 R129 500Sl. White with Navy Blue (132) interior.

The car has 73,147 Original Miles. (That's good and bad).

The car was owned by an elderly gentleman who used it as a pleasure vehicle. He ended up taking ill, and the car sat parked from 2003-2010.

He passed earlier in the year, and his grandson (who I am friends with) inherited the car. He put about $2600 into the following things to get the car back on the road.

-New tires, Brakes, exhaust, driver power window regulator, fluid changes, battery etc.

He had no particular interest in the car, and after some discussion and negotiation. I now own it.

The car needs a lot of work to be 100% but I got it cheap.

I'll make a list of the good and the bad.

The good:

Mechanically runs and drives perfectly.
Leaks Nothing.
Perfect bill of health from 2 mechanics
A/C works and blows cold. (it MAY still even be R12, I have no clue)
Body is straight, and dent and rust free
New tires on 18" AMG wheels.
Has the hardtop
Had the lower cladding and bumpers color matched at some point earlier in it's life.
Soft top in good condition

The bad: (and this is everything I have come up with so far)

Interior Cosmetics - new parts needed:

Seats NEED new upholstery. The leather is dried cracked and split. All power seat functions work.

The interior center console wood is showing its age, it is still in tact and there but it has a section that is faded a bit and has some cracks.

The drivers power window switch works, but it seems like the up position is picky. It almost seems like you have to push down, and then back up without letting go to get the window to go up. The actual electric functions of the window seem fine.

The power mirror adjustment switch is broken, the top piece that you turn left and right to select a mirror and move them is missing.

The portion of the sliding center console cover that covers the ashtray and cigar lighter assembly is missing.

The emergency brake release handle is broken off. I actually have the piece in the car, looks like you could release the brake with a pliers if you needed. I need to replace that piece.

The rear view mirror is there, and the actual mirror glass is in tact, BUT the plastic housing around it has broken off, I actually have the back of the housing but not the front frame around the mirror glass.

Hood pad is deteriorated, and virtually gone. Little pieces of foam sitting on the motor...

Here are the pictures of when I first brought her home: