Multiple electrical failure

Problems began with drained battery. Thought it was bad battery but wasn't. We have a newer alternator. Checked it and it was still good. Traced it down to dome light but thats not all. Other problems have continued. The warning lights that show up on the dash when you start the vehicle come on and off while driving. The battery continues to slowly drain. When I turned on the turn signal the other day it turned off the radio (I was just pulling into the driveway at the time and my husband went out to check the truck and he said the battery was dead so maybe it wasn't the turn signal that turned the radio off - maybe a dead battery did it?). The speed of the heater fan suddenly got faster while I was driving. We have cleaned the battery connections they look good. We don't know where to start to trace this down. Our only thought is the ignition switch. The starter was replaced in the last couple years. This problem originally showed up 2-3 days after Toyota replaced the steering linkage under a recall. Any thoughts?

What year is your pick-up? What motor do you have?
Call your local Autozone and see if they can load test the charging system on the car. The voltage regulator may causing the problems. Check the cables, both ends, make sure they are clean and secure. Make sure the belt has the proper tension. Make sure the connections to the alternator are clean and secure. Make sure the connections to the alternator are not corroded or fatigued.