Today I decided to remove the rear window on the 123 to deal with rust under the rubber molding. When I removed the Glass I did not follow the FSM. I removed the outer metal trim and worried the Glass out with plastic interior/trim removal tools.

Ounce it was out and the rubber was Off I found that the rust was not extremely bad but that the Glass had be sealed with regular house type window putty/Glazing Compound.

From the bits of glass I found in the back of my car while cleaning ; apparently at some time the Prior Owner had replaced the Glass due to original being shattered (replaced with used). Evidently re-sealing it with regular window putty.

Question is it safe and will it work to use Paint Thinner on a rage to wipe up the window putty residue; or is there something Better?

When the PO installed the apparently used rear window glass it cam without the Defogger Grid wires attached. Can these wires be re-soldered to the grid? (Has anyone done this before?)

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84 300D, 82 Volvo 244Gl Diesel

this is normal - it should have been rope style in the rubber seal, correct? Check Chads rear window replacement thread in the body forum.

If you have the cash, try xylene or at least IPA (isopropyl).. which surface are you worried about cleaning?

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When the PO installed the apparently used rear window glass it cam without the Defogger Grid wires attached. Can these wires be re-soldered to the grid? (Has anyone done this before?)

you need a base for the solder to stick to if you are talking about the connection to the grid on the glass. I was inder the impression there were clips there.. no?

I hate rust!

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You're worried about grid wires?

Nothing wrong with looking ahead I guess.

Yes, a rear window defogger I view as a safety feature that I would rather not do without. I noticed when I was removing the window there are some vents back there. My heater works but not hot defoggin air comes out of those vents.

The (-) and (+) copper strips (that I called wires) are there but were I guess left over from the origional window and not attached to the window.
The replacement window that I think was a used one also has no copper strips or wires attached. However, the grid lines (exposed on the inner exterior of the window) all seem OK when I probed with my Ohm Meter.

One Member E-mailed me and said there is a conductive Epoxy. I will do an internet search for that as it should work.
I also saw some stuff in a syringe a long time ago "Liquid Circuit Board" that you could make a circuit board with. Unfortunately I do not remember where I saw it; Radio Shack does not sell it either.

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84 300D, 82 Volvo 244Gl Diesel

Can you post pictures of these vents and copper strips that your talking about?




BTW- I think you mentioned this before when you were rebuilding your rusty lower control arm.... Your car is not an original California car right? It seems to come from the east coast with all that rust!

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1983 123.133 California
- GreaseCar Veg System

I am just now getting back to look at this thread.
The is a pic from the manual showing where the Copper Strips were (there is 2; one on each side of the grid).



After scraping I found that I have a Holy car.

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84 300D, 82 Volvo 244Gl Diesel

These are normally bonded to the window. They are the mechanical strain relief and electricity conductor for between the wire and the delicate trace lines on the window surface.

You need to glue the conductive bars firmly to the window to serve as the mechanical strain relief. Is isn't important that what glue you use be conductive, just that it not come off. You might try the glue they sell in auto parts stores for gluing rear view mirrors back on.

Electrical supply places sell conductive paint pens that you should be able to use to bridge a connection between each trace and the conductor bars. They are sold for repairing circuit boards, so you'll probably need to find someplace that sells to the industry rather than a plain old Radio Shack. I'm sure they are also available elsewhere too. I'd check an auto parts store as its commonly touted in how-to's for repairing the things. You might have to gently scrape the surface of the traces to get a good connection with the conductive paint -- I wouldn't be at all suprised to find they are lightly insulated to prevent users from shorting the traces to the car body (amazing how dumb they can make idiots these days).

Caveat: I've never had occasion to have to try to repair one of these myself so what I say may be totally off base (but I suspect not or I'd have held my tounge). The only time I've had one fail, it was because the entire window got shattered -- they tend not to work too well in little tiny pieces, but fogging isn't a problem either (so I guess it's a double-edged sword ).

Remember to take pictures, I'm sure we could use a (another?) writeup on how to make such a repair.

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'83 300DTurbo http://badges.fuelly.com/images/smallsig-us/318559.png

Broadband: more lies faster.

I am just worried about that purple Tribble escaping into the wild.... aren't they supposed to be on leashes ?

I did not know what a Tribble was - No, I am not a trekkie.

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While you've got the rear window out, now would be a great time to clean your fuel gauge sender, replace the rear speakers, and possibly re-carpet the back.

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$60 OM617 Blank Exhaust Flanges
$110 OM606 Blank Exhaust Flanges
No merc at the moment

How hard was it to remove the rear window? I need to replace the gasket on mine and fix rust around it as you do. I would pay to have a competent glass company reinstall it, but would like to take it out at home so I can fix the rust spots.

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" We have nothing to fear but the main stream media itself . . . ."- Adapted from Franklin D Roosevelt for the 21st century

OBK #55

1998 Lincoln Continental - Sold
Max 1984 300TD 285,000 miles - Sold
The Dee8gonator 1987 560SEC 196,000 miles - Sold
Orgasmatron - 2006 CLS500 90,000 miles
2002 C320 Wagon 122,000 miles
2016 AMG GTS 12,000 miles

Here's the thread where Chad describes his rust repairs.

Remove the window seals to repair the rust

He did a great job and his documentation of it was also very good. I hope that helps.

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" We have nothing to fear but the main stream media itself . . . ."- Adapted from Franklin D Roosevelt for the 21st century

OBK #55

1998 Lincoln Continental - Sold
Max 1984 300TD 285,000 miles - Sold
The Dee8gonator 1987 560SEC 196,000 miles - Sold
Orgasmatron - 2006 CLS500 90,000 miles
2002 C320 Wagon 122,000 miles
2016 AMG GTS 12,000 miles

I would assume, never having taken out the rear screen on a W123, that the copper strips running down each side of the glass are at least similar to the W115. You need to clean these strips well with Deoxit or the like so the solder will bond well: both those on the glass and the ones attached to the lead wires. Since these strips tuck up under the rubber gasket on the inside, I soldered them together then gently filed any stray solder lumps as smooth as possible with a finger nail file to get as good a mechanical seal as possible. Make sure all parts involved are hot enough to make the solder run rather than clump up. You'll see what I mean once you get into it. Use a pen torch instead of an iron if available. I can't see doing it properly without one really. You want the copper contacts right up against eachother rather than connected at intervals with a spot of solder. I tried generic ACE solder first and it did not work so well. I had some high silver content solder I used in a home speaker crossover project a while back and it did the trick nicely. partsexpress.com has what you need on the cheap.

Works like a charm now. A PO had replaced the rear glass at some point and just tucked the leads under the parcel shelf. No end to the shortcuts some folks will take to save a buck or three at the most.

Sam

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Best Regards,
Sam

'76 280 Time Capsule
'00 S430 Long Trips
'91 190E Seeing how far it will go. 366k
'04 American Eagle Motorcoach

Permatex makes a repair kit for rear window defoggers. There's an article about using it here- http://www.rd.com/familyhandyman/content/55830/

I don't think that kit will work. That is for the type of grid that is painted onto the surface of the glass, with grid lines that are about 1/32" wide.

I don't know about the other W123 models, but on my 300CD the lines are REALLY thin and there are a LOT of them - about 1/4" apart running top to bottom instead of side to side. I haven't looked closely enough to be sure, but it looks as if they might actually be hair-thin wires imbedded in the glass.

If that's the case, the permatex kit wouldn't work. If I'm wrong, I'm sure others will chime in and correct me...

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1984 300 Coupe TurboDiesel
Silver blue paint over navy blue interior
2nd owner & 2nd engine in an otherwise
99% original unmolested car
~210k miles on the clock

1986 Ford F250 4x4 Supercab
Charcoal & blue two tone paint over burgundy interior
Banks turbo, DRW, ZF-5 & SMF conversion
152k on the clock - actual mileage unknown