Interesting panel lights problem

[Myros]

The panel lights on my 202 are playing up. The temp display, odometer and clock all dim and brighten OK, but the speedo and gauage lights c ome on bright and then fizzle away to nothing over the next few seconds. I can also detect buzzing interference on the cd changer when this happens if I havethe music on.
I had the pod out yesterday, checked all the bulbs, and put new ones in the gauge illumination and still no change.

Any ideas anyone?

 

[Dec]

Picured is the PCB board for a W202 you might have to go in deep to find the problem, it dose sound like it might be the dimmer. Every thing should dim, including all switches/lihgts at gear stick, temperature controle knobs and courtesy light switches,

Dec

 

[Myros]

thanks Dec

I'll strip it down over the weekend and trust to providence that it's something simple like an easily spotted dry joint.

 

[Dec]

Instrument Cluster W202 PCB (printed circuit board)

For the benefit of others and as I have an old cluster, I took it apart to see what pitfalls may be encounter in dismantling it.

1… In order to access the back of the cluster, the torx screws, located at green arrows in picture, must be removed first.
2… Remove the 2 screws holding the temperature gauge from rear of cluster, pull out to unplug it.
3… If you don’t have an outside temperature gauge fitted, there will be a blanking cover fitted instead, removed the 2 screws holding it and remove.
4… Remove the 3 screws in each of the 3 dials, pull straight up to unplug each dial.
5… Remove 2 screws at large green arrows.
6… Don’t dismantle either the dimmer or clock adjuster knob.
7… Don’t pull or exert any force on either the clock or mileage counter.
8… The PCB board will now lift out of the casing.
9… There is 1 spring attached to the back of the dimmer knob, if you find a loose spring when you finish, then that is where it belongs, this is the only spring inside the cluster.

With care, the PCB board, in its dismantled state, could be tested live in the car, provided the 3 dials and temperature gauge are plugged back in and secured with there screws. Great care should be taken not to damage the dial needles and other components.

IGNITION MUST BE OFF WHILE THE TWO PLUGS TO THE REAR OF THE CLUSTER ARE DISCONECTED FROM THERE SOCKETS, OTHERWISE THE SRS (Airbag) WARNING LIGHT WILL STAY ON, REQUIRING DEALER RESET.

Dec

 

[Myros]

Dec, I thought long and hard about this

and given the distinct lack of fortune I had when i disassembled the mem's cluster on the w210, I decided not to bother. that deceision was aided by your excellent photos and hints. What i ended up doing was taking a feed from the "good" bulbs that illuminate the digital readouts, and using that to power a couple of white leds stuck into the apertures for the dial bulbs. Not perfect, but it works well enough, and I can see the dials at night now.
I just decied that for something which has taken about a tenner and and an hour to fix in an unorthodox way, it wasn't worth going ballistic and incurring a lot of cost and trouble for the orthodox result.

 

[Dec]

Very innovative and a wise approach, you have achieved your goal so that’s all that matters, no one will ever know you have Mickey Mouse lights.

Dec

 

[television]

There is more than one way to kill a cat,well done

 

[Myros]

even weirder

keen readers of my posts know I changed my Blaupunkt TravelPilot for the mem's APS 30 last weekend. Lo and behold, the panel lights and switch illumination have returned to normal. I've ditched the LEDs and gone back to normal tungsten bulbs. There must be something in the blaupunkt set up that was doing it. very weird.