Troubleshooting Lights?

[liquidmonkey]

Have some lights on the main arm which stopped working a few months after buying my JCB 8018 CTS. I've checked the fuses, all ok, and then when i changed out the battery yesterday I noticed a chewed??? cable and was wondering if that was the lights cable? See pic for white circle.
Then I also noticed an odd red item, some sort of lever. White arrow, any idea what that is?
How else can I trouble shoot these darn lights? Getting dark in Sweden now and gonna need them

 

[DaveDCB]

Probably a case of testing the wires at the light fittings see if you have power, if not just trace them back until you get a result.

Red lever could be a slew lock? Or maybe a prop if the cab tilts? @Gunners may know as he has a smaller jcb mini?

 

[Gunners]

Put power to the light unit itself - they get water in them and rot out on older models - could be a simple fix, I've even had bulbs that look fine but are blown somehow.
I agree with Dave, that red lever is probably something to do with the cab tilt, although I never owned an 801 of that era so not too familiar with the design.