ok so you have the updated combo flasher.now you can use the procedures outlined in the 01 manual under lamps to seek out the gremlin.

 

I may know the answer to this! I had the same problem. It happens when both front and rear bulbs aren't working. When one goes out, it fast blinks. When both go out, it buzzes. In my case, at both front and rear right side, corrosion made bad contact, causing heat, melting the leads from the bulbs and recessing them into the plastic base of the bulbs. I found out by wiggling one bulb, which made it go from buzzing to fast blink. I cleaned the contacts, replaced the bulbs and no more buzzing.

 

Having similar problems with my turn signals. Just got a 2004 Ram 3500, and the right side turn signal just began flashing rapidly. I replaced the right side bulb, and it still is flashing rapidly. Anyone with a thought??

 

Turn signal fluid, FILL THE TURN SIGNAL FLUID!! You probably replaced the wrong bulb.