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Odometer stopped working - query
Posted: Mon Jan 01, 2007 5:51 pm
by Highfield
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
Posted: Mon Jan 01, 2007 6:13 pm
by butzsi
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
Posted: Tue Jan 02, 2007 9:53 am
by Highfield
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
Posted: Tue Jan 02, 2007 10:11 am
by Lightweight_911
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.
Source of Problem - Broken Orange Gear ?
Posted: Tue Jan 02, 2007 6:07 pm
by Highfield
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
Posted: Tue Jan 02, 2007 6:17 pm
by Peter
Posted: Tue Jan 02, 2007 6:31 pm
by Lightweight_911
Ian - '65-'77 911 models all used mechanically-driven speedos.
What gearbox is in your car ?
Posted: Tue Jan 02, 2007 6:35 pm
by Highfield
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
Gearbox Photos
Posted: Tue Jan 02, 2007 6:38 pm
by Highfield
Posted: Tue Jan 02, 2007 7:25 pm
by Lightweight_911
Ian - it's adjacent to the drain plug :

Posted: Tue Jan 02, 2007 10:30 pm
by Highfield
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
Posted: Wed Jan 03, 2007 10:48 am
by Highfield
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
Posted: Wed Jan 03, 2007 10:27 pm
by Lightweight_911
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