Problems trying to get a 9F Hornby Evening star loco to run

The power pick up on this version is that the loco chassis is live to rail one side, the tender live to rail the other side. The red wire in the photo is the connection from the loco to the insulated brush connection on the motor. The other brush is connected via the motor body construction to the live side of the tender.

One possibility, if you removed all the coupling rods and took the coupled wheels out of the chassis, they will go back in wrong way round, then there is either no circuit or a dead short on the loco. (I don't think it is possible to get the wheels wrong way around in the tender, but it is an age since I last looked at one of these!)

Old Hornby diagrams here, in case that's helpful, look at 91 and 91A for a start, then follow on to the tender diagrams.

Hello
Thanks for that, I have had a good look at the wheels and the service sheets and have worked out there is a single plastic bush missing from one set of wheels, so I imagine as these are insulators to the side which doesn't take up the current, it would be enough to short out the loco body
I am going to order some of these and see if it makes a difference. I also think the wheels and axles need a bit more of a clean.
I will post back on here when I have done all this
Thanks again

No prying or levering! The best way is applying a rod slightly slimmer than the axle to the axle end, and gently 'drift' them off with taps from a pin hammer. This leaves the wheelseats undamaged, so when replaced, the wheels return true on the axle.

But before removing the wheelsets, are the metal tyred wheels, (uppermost in your picture) live to the chassis block? If so, it's the connection from chassis block to the brush that's the problem. Never having loooked at this particular motor unit, unfortunately I cannot advise on the missing part(s). Hopefully another on this site will know...

Hello
Tested the continuity between track and chassis on the tender and was good. There was no continuity between the chassis and brush as you said, but nothing missing as I found the relevant service sheet.
I then noticed that the little tab coming off of one of the brushes was bent forward to so bent it back and hey presto the model is now running back and forwards, so thanks very much for all your help.
Just one other thing I have lubricated all the joints on the gears at the side of the loco, but still a bit slow, so where the brass bearings connect to the chassis on the axles, are these meant to run dry i.e can they be lubricated or will the lubricant block the current flow to the chassis of the loco?

Those axle bearings are intended to be lubricated. Use a plastic compatible oil or grease, to avoid degrading the plastic components of the wheelsets. There will still be adequate conduction.

There should be a short black wire with spade connectors connected between that tab you bent on the left and a lug on the motor casing just behind it, the tab itself doesn't touch the casing directly. The other brush tab connects to the wire from the tender connection.