The main beam tell-tale on my dash clocks has gone seriously dim.

I can't see the blue light at all in the daytime, so I have sometimes no idea if the main or dipped beam is operating.

Also my dash clocks sit low, so the odometer trip reset hits the top of the steering column cowling.

 

The haynes manual has some guidance on how to remove the clocks.  Is it possible to use a coathanger instead of the tool it mentions?  Does the steering wheel have to come off?  Is the bulb easy to replace?  Would it be straightforward to use an LED instead?

 

It is a blue LED. 
 

I've only removed Mk2 clocks but they only need a Philips screwdriver and fingers to squeeze the speedo clip.

Much easier with steering wheel off, but not vital.

 

Maybe the voltage regulator is failing.  

But I have to ask, why are you using headlights in daylight?

Coming out of a dark car park and forgetting to turn them off?

Setting off in the early morning? 

Edited 24 June, 20197 yr by dvderlm

35 minutes ago, dvderlm said:

It is a blue LED. 
 

 

If it's an LED it will be a white one with a filter as the first sucessful Blue LED wasn't produced till 1993 

I thought Siemens had them from 1977 as Silicon Carbide and very costly, not as good as the Cree Research version commercialised in 1989.

https://www.tu-ilmenau.de/mne-nano/forschung/sic/

https://en.wikipedia.org/wiki/Cree_Inc.

https://www.cree.com/about/history-and-milestones

 

or the 1993 GaN blue that won the Nobel prize..

 

 

 

 

19 hours ago, schneil said:

The haynes manual has some guidance on how to remove the clocks.  Is it possible to use a coathanger instead of the tool it mentions?  Does the steering wheel have to come off?  Is the bulb easy to replace?  Would it be straightforward to use an LED instead?

 

 

If you've for the same kind of dash as my Mk2f then you can get at one of the clock clips (right hand side) by pulling out the main beam switch and using a long screwdriver or something suitably pokey. For the left hand one I pulled my stereo out and could just get to it with my other hand. It was a bit of a faff but you can definitely take them out without the official tool! I think I clicked in the right side and then kept the clock pushing out while i reached for the other - having a spare pair of hands might make it easier.

12 hours ago, dvderlm said:

It is a blue LED. 
 

I've only removed Mk2 clocks but they only need a Philips screwdriver and fingers to squeeze the speedo clip.

Much easier with steering wheel off, but not vital.

 

Maybe the voltage regulator is failing.  

But I have to ask, why are you using headlights in daylight?

Coming out of a dark car park and forgetting to turn them off?

Setting off in the early morning? 

 

I'm pretty sure the voltage regulator is OK, I'm getting 13 something volts when the engine is running.

I use the headlights if it's heavy rain, and dark, say in the evening.  The tell tale bulb works, but it's really dim.  It's been gradually getting worse for some time.

 

I'm pretty sure the tell-tale is a filament bulb with a blue cap.  I think the bulb has darkened with age as the filament is going.

 

See

 

(Blue LEDs, and white LEDs may have been commercially available in 1993, however I can't imagine VW using one in an instrument panel, the costs would have been prohibitive.  It would have been like buying my first CD burner in 2000 for £220, and they were being sold in 2003 for £30)

 

Looking at the golf video, it looks like the clocks have to be dismantled to get at the bulb!  I was hoping for a simple fix. I might see if there is a club member nearby who can help me dismantle them - I don't want to trash a good set of rev counter clocks.

 

For a solution, would a blue LED be OK?  If it's replacing a bulb, would there be a risk of blowing the LED? 

 

If you replace it with a Blue LED you'd need to put a resistor (435 ohms) in series with it too limit the current flow https://www.componentshop.co.uk/led-exp/   https://www.componentshop.co.uk/leds/ultra-bright/5-mm-wide-angle.html 

Well I'll be danged..

3mm white LED below a blue cover in 1992

http://smg.photobucket.com/user/early-1800/media/Cabrio LED/shield_zps06371b36.jpg.html

https://vwgolfmk1.org.uk/forum/index.php?page=topicview&id=how-to_2%2Freplacing-dash-leds

 

 

There is a 3 pin voltage regulator (down to 5 volts I think) on the side of the flexible circuit board on the clocks too.