I have a 98 6th Generation Accord ES I have noticed that, when driving at night , the headlights change brightness on a regular basis. I have also noticed that it does it only when the heater/blower/air-con system is switched on, I found this out after a night trip as I parked up with everything switched off bar the lights to see how regular it did it, but over a 5 min period it didn't do it, yet whilst out it was almost every few seconds. Any ideas as to why this should be? Thanks for looking. Malc.