Who can help with this one?
The switch indicator strip is at the bottom edge of the instrument panel in my Mk2. It holds 3 bulbs for illumination.
According to the workshop manual, the bulbs can be replaced when the instrument panel is folded down.
To me, it looks impossible to reach these without removing the whole panel.
Has anyone experience on replacing these bulbs?
Thanks in advance,

 

Dave on the S Type the dash panel uses two bolts as the hinges so I found the easiest way was to undo the hinge bolts and pull the dash panel out towards you slightly to get at the bulbs. You can do it without removing the hinge bolts but if you drop a bulb it is almost impossible to pick it up as it falls to the back under the wiring loom. Ask me how I know.
Not sure if the Mk2 has the same hinge bolts as the S Type though.

The hinge bolts on the S Type panel circled in yellow.

 

IIRC step one with the S Type is to remove the pull out tray table. The Mk2 does not have a centre front tray table.

 

Cass: that’s a good idea. My hinges are different but the method should work. According to the manual, there is a light filter as part of the switch indicator strip. Do you know its purpose? I‘m wondering if this has aged and reducing the brightness of the bulbs.

Glyn: please inform on the meaning of IIRC.

Does anyone know if the instrument illumination bulbs age and shine yellow rather than white? Or is that an indication of voltage drop due to resistance somewhere in the circuit? Like a permanent dim setting.

Thanks,

 

in my spare S type center panels there is a blue mica plastic film under the front fascia of the switch indicator strip and over the bulbs. I think this mica layer dims the white lettering just enough to not make it intrusive, and it does change the color of the bulbs.
IIRC means "If I Remember Correctly".

 

If I remember correctly.

 

Replacing the switch indicator bulbs in a MK2 is extremely simple.
I suggest disconnecting the battery, so you don't inadvertently short anything to earth while fossicking in the rear of the switch panel.
Open the panel to its full extent. Note; never do this with the scuttle vent open as the operating lever will interfere with the switch indicator panel and break it!!!
The indicator bulbs are at the bottom of the panel closest to the hinges. There are 3 of them.
Using a pair of long nose pliers grab the base of the bulb holder and pull it out. Note this bulb holder is a slide fit into the fixed (welded) bulb carrier. This is not really apparent when you first look at it.
Replace bulb and reverse the process.
If you have difficulty following this, I will supply pictures.
Cheers

 

Bill Mac: thanks for the tip.

I have been experimenting and can report the following:
- Yes the bulbs do seem to age. A new bulb is brighter and whiter.
- Yes there is a bad connection somewhere in the circuit. A bulb connected by a dedicated wire from the battery is brighter.

I‘m going to order a couple of LED bulbs and experiment further…

 

Dave
For the miniscule amount of power drawn by these 3 bulbs I wouldn't bother to chase LEDs.
Cheers

 

Bill,
My interest is to improve the brightness of the instrument illumination. I started the thread on the switch indicator strip because I couldn’t see how to replace these bulbs.
I’ve now obtained one LED bulb to try out. Using dedicated wires from the battery, it’s white and brighter than a normal bulb (no surprise). Mounted into the ammeter in the centre panel, it seems to be bluish-white and not brighter than a standard bulb. I don’t know if this results from bad connections in the circuit. I‘ll check the voltage in the bulb holder. I also want to remove the ammeter and clean it up.
Dave

 

There's only 12 volts in the system, go through the circuit and clean up you bullet connectors, spade terminals and grounds..
You may even run into where the bullet connectors are not soldered, those are the worst, you can solder them or clean them up from the oxidized copper/brass and cadmium plating on the connectors them selves.
It's common place to see all this white powder all over things.

 

After cleaning up the 3 double bullet connectors behind the top edge of the fold-down center panel, the instrument illumination has improved.

When looking into the bulb hole of the ammeter, there seems to be a blue filter screen inside. That may be the reason why the LED bulb did not improve things - there’s an interesting article on the website of classiccarleds explaining effects using LEDs behind filters. Hence, the following question:
- is the instrument illumination (ammeter, fuel gauge, speedo etc) normally white or are coloured filter screens used inside?
Thanks in advance…

 

It's better to avoid trying to colour filter LED light. As I recall, all the instrument and interior lighting in my car was white (or more precisely a yellowy white) apart from possibly the glove box that might have a blue lens. I never understood the purpose of having different levels of brightness for the instruments as the choice seemed to be between useless and not very good.

 

The instrument panel lights on the S type are white bulbs but have a blue plastic screen as can be seen in the attached photo of a spare I have. Not sure if this is the same on the Mk2.

 

Cass
It is the same system on a MK2 but the bezel is different. No fuel tank selector.
Cheers

 

Bill, When you say the same, does that include the blue film?

 

Yes Peter.

 

Dug mine out and it's there. I don't remember any blue effect. In fact, the dull yellow illumination of my Mk2's interior and instrument lighting was about as far from 'Tokyo by Night' as it's possible to be. If that's what Sir William intended, I'll have to invest in blue LEDs!

 

Just confirming the blue filter is definitely there in a MK2.
I have a salvaged centre panel out of a MK2 wreck from 20 years ago which I have been dissecting for gauges and switches.
If Peter needs the blue strips he is welcome to them.

 

Many thank for the offer, Bill. But it turns out, there is, to my surprise, a blue strip in the old panel from my car. I also have a spare from an S type (it has veneered wood), but the spare instruments are carefully stored (buried) behind so may other items, there's no chance of looking at it. as I wrote before, the blue didn't seem to have great effect apart from possibly making the illumination even dimmer.

Still, it would be nice to make a trip to Australia to pick it up.