Odometer stopped working - query

Highfield · Post by **Highfield** » Mon Jan 01, 2007 5:51 pm

The Odometer stopped working on the way home from work - speedo still fine.

I have articles on Pelican and Wayne Dempseys book to refer to, but my speedo is VDO Electronic, and has no cable drive.

If I remove from the car, I have to cut three wires as they cannot be traced for disconnection - I can refix with bullet connectors.

Can I remove the facia and then pull out the mechanism and work on it as though it were cable operated as per the articles I have found.

I cannot find an article on repairing the plastic gears or pot-metal gear on an electronic speedo.

Help as ever gratefully received.

Alternatively, a 150mph 'S' speedo (sensible money) would be welcome - anyone got one for sale in good condition ?

Ian

butzsi · Post by **butzsi** » Mon Jan 01, 2007 6:13 pm

Hi Ian, You need to first remove the time clock from the dash - pull around the outside of the bezel to remove it into the interior of the car. If the force required seems too great go to step 3. If you remove ok as above then put your fingers thro the now exposed hole in the dash, and push the rear of the speedo with your fingers until you can remove from the dash, ALL of the wiring to the speedo is made via lucar connectors that can be easily pulled off (the illumination bulbs in their holders may have to be prised up for removal) use your digital camera or mobile phone to photograph the placement of wiring etc.

Step 3
If the above does not work then you will have to lift the front lid and boot carpet, remove the cardboard bulkhead cover and use a suitable blunt tool to push the speed rearwards into the car interior.

VDO in Birmingham may be able to repair if it is not an integrated circuit problem, otherwise you may have to send to the States.

Happy New Year

Chris

Highfield · Post by **Highfield** » Tue Jan 02, 2007 9:53 am

Thanks Chris,

I should have mentioned that I have removed the speedo from the dash and photographed.

Can I pull out the blu and black wires ? Are these the bulb holders, as they go in to a large connector from which about 4 such wires appear ?

http://i124.photobucket.com/albums/p33/ ... CN1234.jpg

http://i124.photobucket.com/albums/p33/ ... CN1233.jpg

Ian

Lightweight_911 · Post by **Lightweight_911** » Tue Jan 02, 2007 10:11 am

Ian - the black/blue & white/green wires are attached to bulb holders.

Prise the holders out by levering between the casing & the brass 'ring' at the base of the bulb holder with a small screwdriver.

Highfield · Post by **Highfield** » Tue Jan 02, 2007 6:07 pm

Thanks everyone.

Speedo out and dismantled on the kitchen table. You cannot get the inner workings out completely, as the electrical wires are still connected.

This photo shows the orange gear that has missing teeth - can you get them individually, or do I need to find another speedo ?

Anyone got a contact for VDO direct ?

Is this the correct and original speedo for a 1973 911T, and what would an 'S' have had along with the 8,000rpm (?) tacho.

Thanks

Ian

Peter · Post by **Peter** » Tue Jan 02, 2007 6:17 pm

http://www.odometergears.com/subpages/porsche.html

Lightweight_911 · Post by **Lightweight_911** » Tue Jan 02, 2007 6:31 pm

Ian - '65-'77 911 models all used mechanically-driven speedos.

What gearbox is in your car ?

Highfield · Post by **Highfield** » Tue Jan 02, 2007 6:35 pm

Andy,

I have a 5-speed 915 box. The speedo is a 150mph unit.

Where do I find the serial number for it so I can post here for reference ?

Ian

Highfield · Post by **Highfield** » Tue Jan 02, 2007 6:38 pm

Lightweight_911 · Post by **Lightweight_911** » Tue Jan 02, 2007 7:25 pm

Ian - it's adjacent to the drain plug :

Highfield · Post by **Highfield** » Tue Jan 02, 2007 10:30 pm

Peter wrote:http://www.odometergears.com/subpages/porsche.html

Great link - I will order a gear even if I end up changing the speedo for some reason, but for now I am electronic so will use as a speedo only (bummer as I wanted to do some mpg calculations) until the gear arrives.

Ian

Highfield · Post by **Highfield** » Wed Jan 03, 2007 10:48 am

Lightweight_911 wrote:Ian - it's adjacent to the drain plug :

Unfortunately the gearbox is worn down at that point (typical!) and all I have of the number is this :-

Is there any other way to distinguish the model - I think it doesn't have an oil cooler so pre-84 ?

The orange wheel on the speedo has been removed (it crumpled away) so will order a new 20/31 from the linhk above.

Ian

Lightweight_911 · Post by **Lightweight_911** » Wed Jan 03, 2007 10:27 pm

Looks like that serial number could be: 716 0652

- that would make it a 915/44 which uses an electronic speedo

The gearbox was original fitment to '76 Carrera 3.0/911/911S models

DDK - Die Deutschen Klassiker

Odometer stopped working - query

Odometer stopped working - query

Source of Problem - Broken Orange Gear ?

Gearbox Photos