W4 Peckett problem running on DC

[Multigauge]

Hi fonts of all knowledge,

 

Been cleaning the wheels on my Peckett with an old peco wire brush dodad and partway through it stopped working; I didn't notice any shorting.

Placed it on the track and no luck. 

Took the body off to look for loose wires and no none found. Placed it back on the track and it worked. Continued to clean wheels and it stopped working again. 

Also noticed that it doesn't sit true on the track any longer - it seems to have  one wheel above the rail! I suspect both are related...

 

What on earth have I done? 

 

I have checked the blanking plate and it all seems to be secure. I have pulled it off, checked and plugged it back on again.

[PMP]

The axles sit inside the chassis casting held in place by turned bearing collars. 
See picture here of underside of chassis pic no10

https://albionyard.com/2016/12/25/Hornby-masterclass-peckett-w4-r3427/

 

It may be that one of those bearing collars has moved inwards and now sits entirely inside the casting rather than bridging through it. With the construction of the chassis I think you’re on the right path that something has moved out of place when cleaning it. The pickups are very flexible so make sure none of those have twisted or got caught with your re-assembly.
 

The other check to do would be to make sure the coupling rod isn’t bent or twisted which would be very unlikely, but t worth checking if all others draw a blank.

[Multigauge]

@PMPThanks for the link to the Peckett masterclass. It was useful.

 

It now sits squarely on the track. 

 

I have found where the electrical fault lies and it is a loose wire to the blanking plug from one of the pick ups.

Unfortunately I will need to solder the wire back on to one of the sleeved pins - soldering is not my strong point. Nevertheless, I will give it a go once I've gotten hold of a fine tip for my soldering iron.

 

Cheers,