Just a couple of days ago my truck started some weirdness. Using the turn signal sometimes causes all lights to blink, the radio presets to zero out and the engine to falter. Any ideas what to look for?

I'd find an electrical diagram and start checking the ground points for corrosion, wear, or short-circuiting between wires in a harness. Another possibility is a wire harness passing through a hole that has rubbed through the insulation, causing shorting. Hope this helps!

Do you have wiring for a trailer hitch? that frequently causes all kinds of problems like yours.