96 Suburban Electrical Issues

I have a 96 half ton chevy suburban that has electrical issues. When the air conditioning is on my anti-lock brake and regular brake light will come on and disappear seconds later. The fan will shut down for a few seconds then return. On a road trip this past weekend we got new behavior. Whenever the fan level was changed or the air turned on/off, it would disable my cruise control. Not just temporarily it would only return if I shut the vehicle off. Even then it was only a few minutes before the sequence would happen again. Here's the sequence: 1. Change of internal fan/ac settings, 2. anti-lock brake light on, 3. second later regular brake light on, 4. 2 seconds later anti-lock light off, 5. regular brake light off. Tried to use the cruise control then my tackometer and speedometer dropped to zero and reengaged to normal position. Help,
Eli96

First thing is check the grounds....internittant wierd electrical problems are difficult to diagnos and many are caused by bad grounds.
Also check the battery cables for corrosion.