Wireless computer interference
FIle this problem under the "Who knew?" category.
As the days grow shorter I'm riding at night more and more. I have a Niterider headlight/taillight set that I'm using and it gives me good lighting for my rides. Separately I noticed that my Cateye wireless computer wasn't working. Checked the battery, all's good. Then I discovered that half way through a recent ride my computer quit working, and that perhaps coincided with my turning my headlight on.
Sure enough I was able to confirm. So I went to the Cateye instructions (who reads 'em, anyway???) and it specifically says that a battery powered light can interfere with use of the computer. I guess the light blasts out EMI that disrupts the wireless sensor sending signals to the head unit. The computer itself still works but it's not getting any signal from the sensor. Who knew?
So now I have to move things around and see if I can solve the problem. Or build a Faraday cage for the headlight!! Does anyone know if battery powered lights interfere with GPS units? That may be my alternative...