50% Front Heated Windscreen Not Working

Martin Stockwell

Martin Stockwell

Member
VIP Member
T6 Pro
I havnt had the T6 long, so this is the first time I have had a chance to use the front heated screen option as it was a bit misted up this morning.

However, in a few seconds I could see a problem, see picture below (taken badly) where only half of it is working. typically the fault is on the drivers side else it wouldn't be such a problem.

Its going in on Monday for an issue with the sat-nav (on another thread), but has anyone else seen this before, I would have thought it would either work or not, not 50% of it, a perfect straight line from the rear view mirror to the dash...

20181003_070929.jpg
 
The element is two parts covering half the screen each, probably got a wire off on the connections
The plugs for this are behind the black plastic scuttle plate along the bottom of windscreen so need the wipers removed to get to them but if it’s going in anyway prob easier to let VW fix it
 
thanks for the info, gives me some knowledge when I go in with it on Monday so they cant give me the suck through the teeth excuses for not looking at it lol.
 
that's where the fuse was, I havnt got anything to look up what the fuses, I didn't want to pull all of them one by one lol till later. however I pulled all the 30s, and sure enough one has blown. I will get one tonight and hope it doesn't go again else that's another problem to sort...

And as such, I have upgraded to VIP member as well so at least I have some access to some decent diagrams. be nice if they done a printed service/Haynes manual like the good old days lol.
 
Ok. If you have a multimeter.....

You can read the ohms of the outgoing leg and read the resistance. (With the fuses out obviously) and compare the working side to the faulty side.

Sounding like a short.... but is it the screen or cable to the screen?

I'm not sure of the exact spec...

But ohms law would suggest that at 12.6vdc and 25amps the screen should read about 0.5ohms.


Failing all that..... back to VW for a warranty claim?

Keep us posted.
.
 
Probably worth looking to see if there is an obvious short, but sounds like it could be difficult to spot.
Warranty job I think.

Pete
 
Dellmassive said:
Ok. If you have a multimeter.....

You can read the ohms of the outgoing leg and read the resistance. (With the fuses out obviously) and compare the working side to the faulty side.

Sounding like a short.... but is it the screen or cable to the screen?

I'm not sure of the exact spec...

But ohms law would suggest that at 12.6vdc and 25amps the screen should read about 0.5ohms.


Failing all that..... back to VW for a warranty claim?

Keep us posted.
.
Click to expand...
You must be some kind of mind reader lol. That was my next job to calculate the ohms of the screen, you have saved me some time, thanks.

I'll get the multimeter out on the weekend and check. Even if it is a warranty claim, I still like to diagnose the fault as much as possible so I know when the dealer is talking crap or trying to fob you off with some nonsense.

Thanks again.
 
May be difficult to distinguish between a short circuit and 0.5 ohms on many multimeters unless you have a good low ohms range. Also take into consideration the resistance of the meter leads especially on cheaper DIY meters.. Touch the probes together and see what it reads first. Deduct this figure from your readings.

If you can disconnect the windscreen connection, you can at least check for wiring shorts.
 
Just had a quick look at mine while on a break..

Only had a battered cheap work meter..... but it seemed to be reading about 10-20ohms... obviously metering out all the cables and ground points Etc.

So good reading On a working system 10-20 ohms.. each side... ( with system switched off). same reading with the Fuse in or out.... when system on power is fed via inner most Terminal.. outer most goes out to screen..


20181005_105644.jpg

.20181005_105348.jpg

.20181005_105325.jpg

.20181005_104227.jpg

.
 
0.9 and 1.6 ohms..

Just shows you how cak my meter was...

Let's see if we can get someone else to post a reading.... to compare...

Must say yours are very close......
 
It's a 0 reading when together. From what I read the voltcraft self adjusts and compensates for itself, I would have liked a fluke meter but this was on offer when i needed a new one a couple of years ok.
 
RE above . . . . . be careful with those meter probes in the fuse holder. (you dont want to spread the terminals apart or that might cause you more agro with a future poor connection) (always best to just touch the contacts)

.


Bit More again . . . . . So it seems there are a lot of variables....

Got the Fluke meter out today and had a solid 8.6ohms from boths sides . . . .

20181008_154655.jpg

bvut it seems it depends on where you pick up the negitive from . . . . the above reading was from the battery NOG post like this . . .

.
20181008_155056.jpg

.

but look what i got when i used the Grounding nuts behind the lights . . . .


20181008_155116.jpg

.

i got this . . . .

20181008_155107.jpg

.

and i got this reading from the van side of the current shunt on the neg side of the battery. . . . .

20181008_155044.jpg

.

20181008_155047.jpg

so it seams because we are dealing with such low resistances the ground side is making a large difference in any reading . . .

so now looks like a good reading is maybe from 0.3 - 20 ohms (depending on meter and ground point location)

.
 
I think you get funny readings over the shunt because there is always current flowing through it. Shouldn't try to measure resistance over active circuit.
 
All very good points. Just goes to show sometimes it's just not that easy to diagnose some electrical issues. In an ideal world you would disconnect the battery, or try and get a reading on the gound point of the screen...

However, good news is after being at VW today, they say they fixed it.

The morons at the factory connected the positive and negative side of the cables together negating the screen altogether. Lol, those guys in the factory must have had an off day! Thinking about it, the fuses did look like they blew with some force!

Lets see what happens innthr morning if it's listed up.
 
Martin Stockwell said:
All very good points. Just goes to show sometimes it's just not that easy to diagnose some electrical issues. In an ideal world you would disconnect the battery, or try and get a reading on the gound point of the screen...

However, good news is after being at VW today, they say they fixed it.

The morons at the factory connected the positive and negative side of the cables together negating the screen altogether. Lol, those guys in the factory must have had an off day! Thinking about it, the fuses did look like they blew with some force!

Lets see what happens innthr morning if it's listed up.
Click to expand...

Result - glad you got it sorted . . . . . . . . . . . . sometimes you have to wonder lol =]
 
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