Removing and replacing Corsa B speedo?

[Kaison]

I hope someone can help.
I have a Corsa B, originally a 1.2 12v, now has a C20XE.
As it was the 1.2, it never had a rev gauge. - It was also faulty.
So I brought a set with a rev counter.

Before I fit them, I'd like to know just how to remove the speedo and fit the new ones and where to find the wires and which ones go where for the new speedo. It's essentially the same. I just don't know what to expect or look for once I'm behind the dash.

[Melv]

Steering cowling off, remove the screws around the clocks unplug the speedo and that's pretty much it.

I went from a 1.2 8v Merit without a rev counter to a C18XE. I took out the old, non rev counter clocks then simply fitted ones from a sport. The rev counter worked without any wiring.

[Kaison]

I've taken the steering and speedo cowel off, unscrewed the speedo, started pulling it out and realised it's connected to the speedo cable, which has 4 tine screws holding it in place from the other side. I have no way of getting to it from inside the car, without removing the whole dash, or so it looks?

Apon looking at my new speedo with rev counter and offering it up to an Astra speedo of same year, it's totally different on the back, perhaps mechanical and my Corsa replacement is electronic? So by the seems of things, my old clock is mechanical too?

I'm stuck and unsure where to go from here.

Here's a picture of an Astra cluster I have, which I believe is what the old-broken Corsa one will look like behind:


And what my New Corsa one looks like:



Very confused.

[Kaison]

Oh great. Managed to get it removed! Stubborn clip! - Bad news is I was right.

Here's what the old cluster looks like:


Can anyone advise me of where to go from here?
Do I have to get a speedo with mechanical drive? - I assume that means it's mechanical and the new is electronic?