Relay Buzzing Lights Flashing

[zpcg05]

Let me first say that i think this site is great with all the info and knowledge on here. Here is my problem. I have an early 99 f350 7.3 2wd. My problem is occasionaly my relay for my interior lights will start buzzing wile im driving while its parked doesnt make a difference. The interiors lights will start flashing. Now a few things. I replaced the realy which is relay 1 in my fuse block. Didnt make a difference. When this happens my OD light will start flashing while im driving or parked. My radio and pw,pdl lights on door stay illuminated. When i open my door while parked it will stop buzzing and the lights do like there suppose to. Now while im driving and open the door the buzzing will continue. I hope this is enough info if someoone can help me diagnose my problem. Thanks to all

[klhansen]

How old are your batteries?

Usually, relay chatter is caused by low voltage.

[Kanman]

Yup, your batteries have just about had it or your alternator is bad.

[zpcg05]

Batteries are about a year old, altenator is only 1month old,(new not rebuilt).
Somewhere i was reading about that this model truck had a problem with the windshield leaking and the rain would run down onto the GEM module. Could this be the cause of it?