Many of the NTX owners have had problems with the Hella fog lamps that came with the bike. Even though Hella is a premium brand this particular application suffers from the wiring rubbing inside the metal housing and shorting out.
One fix is to bunch any extra wire in the rubber cap at the rear of the assembly but vibration still seems to plague the Hellas on the NTX.
In order to avoid this problem I decided to install LED fog lights to replace the Hellas. I'm using lights from Mondo Moto
http://www.mondomotos.com/. They have two styles, a single LED lamp and a multi
led bulb lamp (the multi LED lamp is currently out of stock). Although the LED housing is made of billet aluminum it is still only 6.7 oz each vs 12.5 oz each for the Hellas.
The Mondo Moto lights come with a complete wiring harness that includes a relay and switch. We don't need all that wiring so if I were to do this again I'd get just the lights and the longest leads possible. The wiring is color coded and of high quality.
I also installed a fuze in each light circuit so if there is ever a short it won't take out the 30A fuze that also provides current to excite the alternator. In the garage these new lights seem to be as bright as the Hellas they replace. I'll know better once I get the bike out on a country road. Mondo Moto claims 800 lumens and a 10 degree pattern. The multi LED lamps have 1000 lumens and a 30 degree pattern.
I believe these new lamps will suffer less from vibration due to their lighter weight and smaller size.
Peter Y.