speedo cheat

[min43]

I recently worked on a 1994 3.0ltr diesel surf.The owner admitted that the speedo had been re-worked so that the speed indicator still worked okay but a switch had been added to stop the milage clock from ticking over.Does anyone know how this was done?Which wires were hacked into and where?Would be very interested to learn more,thanks Glen.

[NEZ]

I recently worked on a 1994 3.0ltr diesel surf.The owner admitted that the speedo had been re-worked so that the speed indicator still worked okay but a switch had been added to stop the milage clock from ticking over.Does anyone know how this was done?Which wires were hacked into and where?Would be very interested to learn more,thanks Glen.

are you serious?
may we all ask why?

nee nar nee nar

[min43]

speedo cheat.

We are forced to pay a road user tax here in nz.all diesel vehicles have to pay.it's based on your milage.it's around $300.00 for 10,000kms.this on top of rising fuel cost,vehicle registration and warrants of fitness.never ends.being able to shut down your milage indicator and being able to reconnect easily therefore has it's advantages.police here have been known to pull a vehicle over in a routine check, or check points, and discreetly check milage.then pull the vehicle over again a few more kms up the road & recheck to see if milage is in fact working.meanwhile there are real crimes being commited elsewhere .unfortunately the police are too busy to attend.Thanks for your reply-Glen.

[NEZ]

That Sounds Like Fun, And I Thought We Had It Bad!!!!

[dieselboy]

on some cars, the mileage is taken from a sensor in the rear diff.. i dunno if the surfs are the same, but if there is a plug on the diff case then that may be where you can start?
otherwise i would have thought it would still be electronic, and read from the gearbox output?
i doubt its mechanic, like old cars.. but to be really honest, i dont know. just guessing

[RodLeach]

If i wanted to do give it a try id start by removing the clocks an checking out what the unit was like, see if there is an obvious way to do it.

Its illegal here so no one would really be able to say how its done 'cuz they shouldn't be looking!

[dieselboy]

If i wanted to do give it a try id start by removing the clocks an checking out what the unit was like, see if there is an obvious way to do it.

Its illegal here so no one would really be able to say how its done 'cuz they shouldn't be looking!

yea they frown upon that sort of thing... lol
plus, you dont want to lie about mileage cos when it comes to selling its a false sale, and i'd hate to have that done to me but i probably would never find out tho

[min43]

Needless to say it can be done and has been as I earlier mentioned.Thinking on it there are two places to tap in.At the trans where the speedo sensor is located or behind the instrument cluster.Guess I'll get the multimeter out and have a look around.Purely for curiosity reasons only of course.But thanks for your replies,I do appreciate the feed back.Here's a thought though,perhaps having a switch installed adds value to your vehicle.The new owner could be like minded who knows.

[Macca81]

now im just taking a guesse here... but im led to believe that its an electonic signal for the speedo. the speedo and odo are meant to run off the same circuit. if this fellow that has done it says he has a "switch" for it, then i would have to believe that the signal runs from the transfer to the speedo then to the odo... so he would have cut the wires between the speedo and the odo and installed a switch in place... so just look for any wire that run directly between the 2 and that should be it. i cant imagine tehre would be more than one wire running between the speedo and odo...



sorry if thats confusing at all but i just typed it as i was thinking it...

[Apache]

There are two speed sensors. Both feed the ECU, and disconnecting one of them would play funny bu99ers with the ECU.

If i was going to do it (and I'm not ) I would look at the instrument panel itself, and look for power to the mechanism that moves the odo. it will be a separate mechanism to the speedo as they do different things.

[Macca81]

theres 2 ey?? interesting...


definatly DONT disconect anything BEFORE the ECU, particularly if it has 2 sensors as if the ECU notices that the 2 dont give the same reading then it may well start doing some pretty stupid shite... the instrument panel is definatly the way to go.


apache, altho the mechanisms for the speedo and the odo do different things, they would both still recieve the same signal i would rekon... unless one sensor is for the odo and the other is for the speedo... but i doubt that would be the case, the 2 sensors would have to be for the ECU, to correlate the correct data...

[Apache]

They'll both receive a signal from the ECU relating to speed, but they'll handle it in a different way.

i'm guessing but 99% sure that the (electronic version) speedo will either use a pulse counter and turn that into a varying DC voltage to drive the moving coil meter speedo, or will receive a varing DC voltage from the ECU. The ODO might work in a similar way, but use the varying DC voltage from the ECU to drive a geared motor to drive the ODO, or uses the varying voltage (if a low level signal) to drive a DC amplifier to power the ODO in the same way.

I reckon there will be a motor type actuator for the ODO. Cut a feed to that, ODO stops, speedo carrys on.