My 98 Grand Caravan has what sounds like a relay chattering when I turn the headlights on. It seems to happen more when it has been running for a while, and also when I use the left or right turn signal. One time, I put the left turn signal on, and there was no flash or sound or anything, but that has never happened again.
I have cleaned the battery posts, but still the same.
The chatter sounds like it is in the dash, and I can't hear anything when listening under the hood. As soon as I turn off the head lights, the chatter stops.
Any thoughts/suggestions.

when you hear the sound, do the headlights also flicker?

when you hear the sound, do the headlights also flicker?

They seem to flicker a bit, but it doesn't appear that they flicker with each chatter of the relay.

Are you coming up with a theory? Thanks.

i'm thinking you have a bad relay

Well I had the dealer look at it, and they said it was the day time running lights module that was a bit loose. They repositioned it, and it is better, but I am not convinced that it is totally fixed. Time will tell.