Volkswagen Eos Forum banner

1 - 8 of 8 Posts

·
Registered
Joined
·
6,178 Posts
Discussion Starter #1
My 2007 TDi sport now has some broken tracks on the rear heated screen. I'm a bit miffed about it because condensation from previous years and owners has caused their very thin flimsy copper tracks to corrode and go open circuit. Repairs using silver paint have been temporary and a waste of time. They look ugly, and as soon as one break is repaired another in a weak area breaks.

I probably have to bite the bullet for a new rear screen glass one day, but oh it is such a pity that VW have used more fine tracks in the screen track instead of fewer wider with a higher copper density.

A problem with all car electric rear screen heaters is they demist, but the moist air still hangs around in the void space at the rear. We have started rolling down the rear windows which helps. But here's something I'm just trialling.

There are many electric fan driven heaters around on Fleabay. Most are 10 amps or around 140 watts. I can tell you that holding your hand in front does not impress - but the watts are in the airflow, 10 amps is about the safe limit for most cigar sockets, and even a few degrees increase in air temperature will hold a lot of moisture and most important there should be no cracked screen glass!

I decided on a ceramic element type. These units are pretty cheap and cheerful, although they do have over temperature cut-outs. A fan heater cannot be mounted on the shelf! It stows in the trunk when the roof is lowered.

I poked around the upholstery at the top of the center seat, just above the ski aperture and found a nice tight gap that would take and hold something thin. The fan heater shipped with a U shaped bracket which I stripped off, together with the bracket 'ears' that made it look like Shrek.

All cars these days switch off the cigar accessory sockets with the ignition. Although the fan heater has an off/cold/hot switch, running wires forwards to the cockpit for manual control is just horribly messy.

Since the accessory sockets come on with the ignition I decided to design a simple 6 minute relay controlled timer that starts every time the ignition is switched on. I'm using the EOS rear accessory socket and the controller drops nicely into the ash tray. The wiring can be partially hidden by squeezing it between the seat and the center panel upholstery. I haven't explored yet whether it could be completely hidden. But as it is, the unit and wiring is for Winter, and easily removed when Spring arrives.

6 minutes seems about the right amount of 'on' time, but that's easily increased and you can always turn off the ignition and back on for another 6 minutes.

I'm pleased with how it looks from outside and inside. It doesn't stop the top operating either because it is set back just a tad from the rear shelf.

I've posted my pics. The only downside is the fan is noisier than I would like but OK once my TDi is rolling. It's a centrifugal fan running quite fast with a plastic impellor pushing out warm air in just the right direction - upwards and to one side.

Enjoy! :) Vox
 

Attachments

·
Registered
Joined
·
6,178 Posts
Discussion Starter #4
Yes that's what I said!

The EOS heated screen is printed with very narrow tracks which means they carry a high current density for their size. As soon as you add conductive paint with very low resistance over a break, you increase current through the rest of the track. If the tracks have spent many years covered in condensation, they will have pitted.

Then, when you repair one join, you will get another burnout break somewhere else along the line. Repair that, the current goes up again and you get another burnout break somewhere else.

Conductive or silver paint is fine for minor damage on otherwise newish screens. But when condensation and moisture has caused the metal tracks to lose their metal content, it will not work. Repairs look horrible and silver from inside and out.
 

·
Registered
Joined
·
1,471 Posts
I had my rear screen replaced under warranty last summer because the top two bars didn't work. I am beginning to wonder if this is a problem for the EOS as I haven't had this problem on any previous cars I have owned.****
 

·
Registered
Joined
·
6,178 Posts
Discussion Starter #6
Probably correct!

I have a 13 year old Renault Estate sitting in my driveway, never a problem with the rear screen heated glass (excluding damage to parcels on the inside shelf - watch that!)

When I compare the two rear glasses, the VW glass has twice as many lines of half the width compared to the Renault and virtually impossible to neatly paint repair without a microscope. Add to that the propensity for more condensation inside the EOS cabin migrating to the rear, due to leaks and water getting in as you open the door in the rain.

Some tech. in a white coat probably did lab tests on the eveness of screen glass heating, produced lots of graphs and spreadsheet data to justify their design decision, but didn't consider the operating environment in a Cabriolet and premature failure caused by moisture..

There you have it. Insufficient copper density spread across thinner printed wires and a very expensive part and labor to replace if there's no warranty. Even if there is, new car buyers are still paying the warranty costs. I'm glad they still sell a lot of Golfs to prop up the EOS warranties!

I would love a rear screen with the wires inside the glass, but that will never happen.

Remember, you used to buy those heated rear screen addons before they built them in? They printed the tracks on flexible Mylar plastic which was rolled out across the inside of the glass. Perhaps it will come to that one day.
 

·
Registered
Joined
·
1,471 Posts
Probably correct!

I have a 13 year old Renault Estate sitting in my driveway, never a problem with the rear screen heated glass (excluding damage to parcels on the inside shelf - watch that!)

When I compare the two rear glasses, the VW glass has twice as many lines of half the width compared to the Renault and virtually impossible to neatly paint repair without a microscope. Add to that the propensity for more condensation inside the EOS cabin migrating to the rear, due to leaks and water getting in as you open the door in the rain.

Some tech. in a white coat probably did lab tests on the eveness of screen glass heating, produced lots of graphs and spreadsheet data to justify their design decision, but didn't consider the operating environment in a Cabriolet and premature failure caused by moisture..

There you have it. Insufficient copper density spread across thinner printed wires and a very expensive part and labor to replace if there's no warranty. Even if there is, new car buyers are still paying the warranty costs. I'm glad they still sell a lot of Golfs to prop up the EOS warranties!

I would love a rear screen with the wires inside the glass, but that will never happen.

Remember, you used to buy those heated rear screen addons before they built them in? They printed the tracks on flexible Mylar plastic which was rolled out across the inside of the glass. Perhaps it will come to that one day.
That's because Ford own the Pattern for the wires being laminated inside the glass as on their quick clear front screens, and only allow BMW to use it as part payment for selling them Range Rover. ****
 

·
Registered
Joined
·
171 Posts
I wonder if this idea could be built into the ski hatch box and wired and trimmed to be pretty much a "stealth" installation? A bit of MDF here, red leather there, cable and ducting, hmmmm.;)
Yet another project for my daydreaming hours!!!
Regards,
John
 
1 - 8 of 8 Posts
Top