Speedo drive - what voltage?

[shn7]

Having got my car running with new speedo and gearbox drive (electrical not mechnical) the speedo doesn't work ☹️ No speed and no odometer movement.

 

I'm assuming the drive is simply a small dynamo which when spinning should produce a voltage.

 

So to diagnose this I first removed the drive from the gearbox and whilst still wired in attach an electric drill and span it in both directions. Still nothing at the speedo end.

 

Now having removed the drive completely from the car and put a volt meter across the wires from the drive and again spun with a drill I'm not getting a voltage.

 

Questions:

1 - Am I correct in thinking I should be getting a voltage of some sort?

2 - Is the drill (battery) spinning fast enough to create any voltage at all?

3 - What voltage range does the speedo expect?

 

Any help gratefully rec'd.

 

Steve.

[allen]

I still have a mexhanical speedo (plus bike speedo), surely the sender is hall effect, sending a pulse, not generating a voltage 🤔

[shn7]

Allen, suspect you're right and I was being naive and guessing. What I need is a good way to diagnose where the fault lies.

 

Steve.

[allen]

Have you checked continuity on the wiring?

[shn7]

Not yet. It is a brand new CC supplied loom so should 🤔 be ok. I will do so though.

 

Steve.

[shn7]

Seems it ain't working because the drive from the gearbox isn't turning ☹️ ☹️ ☹️

 

Looks like it's time to remove the engine/gearbox again as I can only presume there is something missing internally from the gearbox. Any suggest somewhere in the chichester area that would be able to sort it if I deliver the gearbox?

 

Not a happy bunny.

 

Steve.