juelladeville

Hi all! This is my first post and I need some input as to what could be wrong with my vehicle.

I have a 2001 2500 HD 8.1L with 128,000 miles, and my truck is a jerk. Just recently as it started getting cold in the morning (within the last week or two) I have gone to unlock the doors to get in and my remote wouldn't work. Hmm, ok, the batteries are dead. I unlocked it with the key and pushed the button on the door. No power. I got in to start and turned the key all the way to run. No power. I tried again and it started a little, then died. Took 4 times to get it to run. It reset all settings on my stereo and reset the clock to 12:00am. It has done this about 4 times, only in the morning after it has been cold overnight.
NOW what it is doing (last few days it started FINE on the first try) when I come up to a stoplight, foot on the brake at a near stop, all the lights come on the dash (battery light, check engine, ABS, parking brake, airbag) and the gauges move around a bit. The stereo shuts off and then comes back on, but doesn't reset completely. My truck doesn't die. The lights only are on long enough to flash, then everything returns to normal. It does this just before it gets to normal operating temp (about 210 degrees.)
Any idea as to what is going on? I have heard alternator, battery cable, ignition switch, starter relay. I am going to test the alternator and battery but am just looking for ideas as to what is going on here... any help is appreciated. Thank you so much!!