Outer Limits 4x4 Board

Hi, I need some help please!

I am trying to wire up 2 new worklights to existing wiring on my roofrack. My old lights worked fine just one of the mounts broke and wanted to upgrade. All my accessories are hooked up through a marine switchboard with each accessory on an individualy fused(running 15 amp fuses) toggle switch which works fine with everything else. Getting 16.8 volts at every switch. My problem is the new lights just will not work on the existing wiring. I have tried them hard wired to my battery at 16.8 volts and no problem. Have tried them through the cig socket plug on same switchboard, no problem. Have checked voltage at the wiring with the switch flicked on and it too is at 16.8 volts. The old lights work fine when hooked back up. Have had this setup for 5 years and never missed a beat.

Can someone please tell me wtf is going on? TIA

http://www.ebay.com.au/itm/2x-LED-Work- ... RTM1769189" onclick="window.open(this.href);return false;

These are the lights in question

May be too simple but have you swapped positive negatives as led's will only run one way.

Other thing could be a dud set of lights

not too sure if you need a diode on this setup..

i ran a led as a reverse wired in
and only one diode
setup another camp light on the same line and kept blowing fuses ALOT
ended up disconnecting the diode and worked fine
ever since

now i need to run 2diodes in line to not blow again