Electronic Speedo Problems

[Zcoota]

I'm in the process of updating the mechanical speedo in my County to an electronic jobbie. Just wondering if anyone here has any experience here with fixing the gremlins in them. The unit I have is a VDO with a VDO sender. Right now I'm having two problems with it;

1) The LCD odometer only sometimes comes to life, when it does the needle moves to the 0kph point and it responds to the trip meter button. Most of the time the odometer is blank when it powers up and the needle moves to below zero.

2) On the rare occasion when it works the odometer ticks over properly but the speedo needle is really sluggish (it takes about 5 minutes to swing from zero to 100kph), now I know my Isuzu is slow but it ain't that slow....[tonguewink]

Has anyone here seen that sort of behaviour ? Any thoughts or do I just have a dud speedo .

Cheers,

Mark

[Red90]

Your speedometer is broken.

[Red90]

What exact sender are you using and how exactly is it wired?

[Zcoota]

I've got a horrible feeling its a dud. The seller didn't push the point too much and just refunded me when I asked him about it and described my problems and hasn't said anything since.

The sender I'm using is a VDO YBE100530, from what I can gather its straight 12v +ve and -ve to the respective terminal on the sender and the signlal wire to pin 8 on the speedo. -ve to Pin 3 on the speedo and +12V to Pin 4.

I think the signal is ok as the odometer ticks over when the unit decides to fire up its just intermittent as to if it will turn on or not.....very confusing.



If the unit is off I can manually swing the needle over to the full speed and when powered up it swings all the way back past 0kph.

The fact that it starts sometimes and then the needle is slow has me stumped, I'm wondering the crystal is failing so the microprocessor is not ticking over correctly ?

[Red90]

IThe sender I'm using is a VDO YBE100530, from what I can gather its straight 12v +ve and -ve to the respective terminal on the sender and the signal wire to pin 8 on the speedo. -ve to Pin 3 on the speedo and +12V to Pin 4.

Sender wires must go to both 6 and 8. It is an open collector hall effect sender. Add that jumper and see if it helps. See below. Ignore the wire colours.

149438

[Zcoota]

I’ve had a shot at that with not much luck, it’s behaving in the same manner. Thanks anyway

[Zcoota]

Turns out it was a dud speedo, I managed to score another with a job lot of parts, plugged it in and it works a treat