Do you know your starter is working? It's also easy to check, just put some wire, screwdriver, metal piece what make contact between thick and thin wires on starter... Be careful do not touch anywhere else with that tool you use, if touched thick wire to ground, it can just melt off...

I fiddled around with some more stuff and got it to turn but it only turned sometimes and other times either nothing, or a whiirring noise. I'm sick of the problem, its a nicely rebuilt starter and he's already checked it over once before and found it to be perfect so he suggested checking wiring in the car.

Its not done this before. He's asked for it back again so back it'll go, I've removed it ready.

Is the mass cable from the gearbox to the battery fixed wel. Are the connectors well fixed to the cables?

They are indeed. And I've cleaned and reattached things so many times now. I'm a bit sick of it now.

Only thing left is maybe the startermotor solonoid mal functioning? It has to make the contact and pulling the bendix forward...? Don't you have an other starter to test if the wiring is the culprit?

The starter got to the guy that rebuilt it, today. Hopefully it's just that.

No I have no other starters unfortunately. I used to have a bucket full of them that I used over the years but they all went and then I had to buy them online. I got so sick of them lasting as little as a year so I got an old one and had it rebuilt.

Sadly, spares have become unavailable for the rebuild of this one. The motor itself is OK but there's a fault with the clutch that swings the gear across.
So I've ordered a new replacement from him at £70. From his supplier it will be a Polish one. I have to give it a go, but what a shame. At least it's not Chinese. Time will tell if that has any effect.

I wouldn't mind a Chinese part but I've universally bad experience with those.

Yes they are made of chinesium....

Sad isn't it. I miss the starter noise of the original units. Even my rebuilt one didn't sound in character.

Anyway, I should get it on Monday, I'll fit it Monday or Tuesday and I imagine it'll be fine. But I still wonder if I've sorted the occasional slow turning of the motor. I give up cleaning anything else! I do have a replacement used ignition block just in case.

Car is booked for MOT on Wednesday so it obviously needs to be working.

good luck.