Want rev counter clocks but have a mechanical speedo?

[Andy M]

Well you need to convert to an electronic speedo

Apparently this is only possible if you have ABS or a gearbox transducer...total cr@p!!!

I am under the impression that all clocks with tacho\'s have an electronic speedo, or the majority do. Which is a problem if you have cable drive!

You will need a screwdriver (Philips), new clocks with rev counter, a flat-blade screwdriver OR a small torx T3 bit.

Remove 3 screws under the column shroud, and 2 at the front. Remove shrouds.
Remove 2 screws securing the clock trim and remove.
Remove the clock securing screws and release the clocks by depressing the tab. Pull the clocks away and release the speedo cable by depressing the clip and pulling it off.

Now this is where the fun bit begins.
Unclip the face of the clocks by prising the black tabs, and the clear face comes away leaving the back and the separate parts (fuel temp speedo etc). Turn the clocks over and look at the centre speedo section. Around where the speedo cable plugs in you will notice 4 screws that secure the speedo to the clocks case. Remove these, unplug the small flexipcb plug and pull out the speedo.
Pull of the speedo needle and then remove the face by removing the 2 screws on the front. Your left with a small unit with the protruding speedo drive connector.
Now remember the small black plug you unplugged before? You need to chop this off, along with some flexipcb (about an inch and a half is good)
Plug the black plug back into the speedo unit and solder 3 wires to the flexipcb, one on each track. This is accomplished by scraping away the varnish to reveal bright copper which the solder will adhere to. Don\'t apply excess heat else it will melt.
Trim the wires to about a foot length, looking from the front of the small speedo unit, the bottom wire should be black, the middle red/blue and the top brown.
You now need to unclip the multiplug from the dash which the clocks plug into, this is done by depressing the clip and pulling.
On the plug you need to locate the following wires..

Black (Ignition
Brown (Ground)
Red/Blue (Speed Pulse)

Using an appropriate method (splicing and soldering is what I did) attach each flying wire you made to the appropriate wire on the multiplug. It is easy when using colour coded wire. Insulate well.
You now need to reconnect the speedo cable to the small speedo unit and get the speedo unit located somewhere behind the clocks where it is held secure and will not move/rattle. I found this easy by just experimenting, and after a few seconds i managed to wedge it in nicely.
Refit your new clocks and turn on the ignition. You should see the speedo needle move a tad to initialise it. If not then you have made a wiring mistake with the brown and black wires.

I would now recommend going for a drive to test it works fine, you will notice a working tacho with no wiring needed, and also the speedo.

Refit trim as per removal and admire your work (and my research!)

With reference to speedo accuracy, i did this to a mates 1.2 8v LS and fitted 1.4 sport clocks. The end result was they under read by 2mph. They were spot on when tested with another car with an electronic speedo, and also they under-read so there\'s no chance of you going through a camera. You can test this to double check if you like.

Any queries post below and i will answer every one of them!

Maybe this could be made a How-2??

Andy

[kyler000]

I have been waiting for someonw to come up with a plan like that. i have a full SRi replica part from the bloomin clocks. An easier way would be to find the mechanical driven clocks n plug rite in. So let me get this rite.

I have a ls 8 valve with massive speedo clock. I go tot he scrappy and get the ecectronic clocks and do as ur tutorial has said and il hav the clocks working perfectly, if so ur a flippin genius. Well done.

[j1400]

Or just use clocks which stat at 10mph which are mechanical speedo with a rev gauge.
The electric clocks start at 0mph

save lots of f**king about.

[kyler000]

j1400 - so its jus a matter of gettin the electronic clocks and switchin the speedo from the old diesel one into it and tats all there is 2 it?

[j1400]

I\'m not sure I understand your question.

The rev gauge bit of the clocks is electric and requires a signal from the coil(or ecu) to work

the speedo bit can be either electric or mechanical.

If your car has a speedo starting at 10pmh then you have mechanical clocks, and you need to swap in clocks from a corsa with a rev gauge and the speedo starting at 10mph, if you have a speedo starting at 0mph then you need a set fo clocks starting at 0

For diesels it\'s different as they don\'t have a rev singal like the petrol cars as they have no ignition or ecu\'s on them.

[kyler000]

Yea know tat, theres a code at the bottom of the speedo i need w-1850. Just really hard to come by,hoping there was some way of gettin round it but thanks anyway.

[kyler000]

wonder if i swap the rev counter out of the diesel one i have, with an electric rev counter from the petrol wud tat work?

[Corsa_Buoy]

Good timing m8, been thinking about this for a while, I hope my speedo starts at 0 then I know it\'s electrical, if it ain\'t then I got to find me a speedo with a rev counter on it that starts from 10, or I just follow yur complicated guide on soldering and messin with car electrics, doe\'s sound bit dogdy.

One thing also, what about the mileage, I don\'t wanna put a 70,000 speedo into a 55,000 mileage car, there got to be a way of adjusting mileage on a speedo!!

[j1400]

not one that mods will lwt be poted on a public forum I\'m afraid.

[kyler000]

i wonder if i swap the rev counter out of the diesel one i have, with an electric rev counter from the petrol wud tat work?

[Corsa_Buoy]

[quote=\"kyler000\"]i wonder if i swap the rev counter out of the diesel one i have, with an electric rev counter from the petrol wud tat work?[/quote]

I don\'t think that will work, as diesel ones are totally different to petrol, like J1400 said \"For diesels it\'s different as they don\'t have a rev singal like the petrol cars as they have no ignition or ecu\'s on them.\"

[Corsa_Buoy]

[quote=\"j1400\"]not one that mods will lwt be poted on a public forum I\'m afraid.[/quote]

Yes, I new this would happen, people everywhere would be adjusting the mileage on there corsa\'s if someone said something here.
I will find out in a much more descreet way.