Adjusting Idle and brakes wiring harness
 

Last summer/fall my idle speed suddenly got way high, like 1100 plus and it was hard to deal with at stop lights etc. So I turned the adjustment all the way down and it just barely made any difference. Until about mid December then it suddenly went way down again and would barely run. Until I compensated for that with Power Service which has always seemed to raise my idle speed. Now without supplement it won't stay at idle, it just dies. Today was pretty so I went out and re adjusted my idle speed again back up to about 750+ rpm in gear. 1) Why would my idle speed be fluctuating so wildly occasionally? Have I got bad accelerator cable somewhere possibly?
#2) Back in the fall I unplugged the wiring harness from below the master cylinder to give my arms some room to adjust the idle. When I plugged it back and cranked the truck my brake and ABS light stayed on since then. Brakes work but I'm sure the ABS doesn't. When first start up on rainy mornings my back brakes will lock up real easy. After I run a minute they don't normally lock up, but I'm sure they would jamming the pedal in an emergency. What could I have done just un plugging and plugging back? Where can I look for a blown fuse?