So for maybe the last 2 months my cb has been making a weird hum thats sounded like it was coming from the ecu. Well its not. Today I was jumping my explorer (been sitting for 3 weeks with alarm system on) and finally made the noise when the hood was up. Sounds like it may be coming from the emissions box/coil area. The coil is about a year old, so im pretty sure its not that. The sound is almost an electrical hum/buzz. Its sporadic at best and happens usually at a warmed up idle so between 600 and 1200k rpms ive heard it. Any would be awesome. Thanks