Skywatcher EQ5 pro synscan declination axis issue

[Unreliable]

Hi all,
 
Obvious newbie I'm afraid. I acquired the above mount a couple of years ago second hand and the declination axis has always misbehaved a little but this has got worse over time.   

About 18 months ago I stripped it and degreased/regreased with white lithium grease following the astronomy boy guide without finding any glaringly obvious issues.

It had been used lightly in my ownership, with a 200mm reflector, balanced as well as I could, and this was the scope I purchased it with.
 Initially it made a lot of noise when in motion compared to the RA axis and would often move in the direction it had moved in last, regardless of which direction you asked it to.  

After 6 months in storage during a house move it is now refusing to move at all except in the highest slew rate setting, and even then will not always moved when a scope is mounted. It is still awfully noisy, and it still sets off in whichever direction it feels rather than the one requested. at lower slew rates you can see the motor trying to turn the gears but without progress
 
I briefly connected the Dec axis motor directly to the controller (rather than via the RA axis motor as usual) and commanded it as if it were the RA axis and the issues persisted. I can turn the axis without difficulty myself (with the "thumbwheels"), the teeth of the gears appear to be engaging ok, the clutch engages and releases ok, I am using a skywatcher skytank that has been fully charged.  

I have been considering changing the stepper motor but cannot seem to find one easily.  Do you guys think motor replacement would be sensible, if so do you know a good source for either a skywatcher specific or generic equivalent motor in the UK?  Are there any other avenues I should be pursuing?
Many thanks in advance for any replies.

[Dr_Ju_ju]

The Importers\Distributors ore Optical Vision (http://www.opticalvision.co.uk/) and they do the spares...  but before then, you say both motors moves, but only at high slew rates and loaded ?  so I'd first check that the wiring is good & that the motors are actually being driven correctly (4 wire steppers)...

[Unreliable]

Hi, thanks for the reply. Last night I swapped the motors around and lo and behold the fault swapped from one to the other. A bit of fiddling and I'm pretty sure it's somewhere in the wiring between the "Dec in" socket and the motor. Thanks for your help!

[Dr_Ju_ju]

If they are the Standard 8 pole DIN plugs & sockets, it's relatively easy to renew or rewire them.