Brightening the speedo display on a post 52 French Traction

For post July 52 Tractions (Malle Bombe) the Jaeger speedo is lit by 2 bulbs at the bottom with the light reflected up the case on the inside. On a 6v car they are 5 watt and on the Grey background it doesn’t make it easy to see what speed your doing in the dark/in a tunnel etc.

Now you can improve things if you remove the speedo head from the car and take the glass off to get access to the display parts. Getting it out means taking the steering wheel off, undoing the screws at the bottom left, under the speedo and the centre clip on the screen surround frame.

Now to get it far enough forward you need to undo the 2 nuts at each side of the centre line (8mm socket) of the speedo head to let the frame come away. Whilst your working ‘backwards by feel but it’s not to difficult.

Once the head is loose from the frame you can pull the frame forward and off and you can then get access to the see the  wiring to disconnect it (it’s colour coded so no problems putting it back) with a 7mm spanner/socket for the retaining nuts. I started with the ammeter and then the fuel gauge. Once you have room you can disconnect the speedo cable and pull out the 2 bulb holders. BTW it can be done without disconnecting the speedo cable at the gearbox as there is enough slack (on a small bodied car anyway).

Once freed from the car the face with the speed transfers actually comes apart with a minimal amount of effort once you remove the surround and glass and when you look at the rear face it’s simply alloy. That face is what the light bounces off to light up the display and whilst it may look OK after 62+ years it will have some tarnish.

You can gently clean the actual face itself with something very mild, I used a hand wipe. Now to the reflective face. If your careful, place it face down on a soft cloth so it doesn’t get damaged, and using some Autoglym metal polish, you can clean it up to a mirror shine. It does take a bit of effort but DO NO USE any liquid solvent on it as it can track over onto the  painted face and damage the finish.

These images shows the dirt that came off mine and the polished rear side.

Now when you reassemble (in reverse order) you can see where when it was originally built there were some ‘spacing’ pads (some shown in the image) which will have gone hard over the years. I replaced mine with some ‘Blue Tack’ as it is pretty inert, stays soft, will compress and hold and shouldn’t damage the coatings. Same applies to the glass which is spaced off the dial as well. Using the BlueTack should stop any of those annoying vibration noises you sometimes get as well.

Once you have cleaned the glass and refitted the seal and glass surround, tape around the outside the glass surround to the body to seal things up to stop any dust ingress. I used some canvas type cable tape, not vinyl, as it’s a lot like what came off when disassembling, if a different colour.

Now for those running or going to 12v then you can source 10 watt incandescent bulbs, but even those aren’t great so I decided to try and go to LED. Now they aren’t the cheapest out there at £14.69 a pair delivered, but Ring Filament Style LED – R10W 12V – 3000K do make an improvement even on a 67 year old car. (4k would have been whiter but I couldn’t find any). Now the LED’s are not ‘dimmable’ so I bypassed the resistor switch, with incandescent bulbs you can leave it in the system if you feel it’s distracting.

Cleaned Speedo viewed from the drivers seat in the dark (with 12v LED bulbs)

All told it took a couple of hours, but was worth the effort as I also replaced the fuel gauge  which had never worked for 7 years, with one from LeBoncoin.

It may be possible to do something similar to brighten up an earlier Jaeger speedo head (black faced) but not having seen one close up can’t be certain.

• This topic was modified 4 years, 11 months ago by David Faulkner. Reason: Spelling error