trouble starting

[suxatpball]

So sometimes when i turn my key to ON and i wait for my "wait to start" light to go off, as soon as i turn the key it makes a "clicking" sound for a sec as soon as the "wait to start" light comes on. (this started about a week ago and only does it sometimes) well last night im changing my oil everything goes good. so i run up the road about a mile to the gas station. i come back out to my truck and when i go to start it the "wait to start" light goes off but the truck just cranks when i try to start it. so i turn off the key make sure my TW chip is still in place correctly. so i try it again and the truck starts up fine. So then the truck sits over night and i go to start it this morning and when the key is turned to "on" i get that clicking sound again and all the guage lights that usually come on are kind of flickering like it has very little power. so again i do a quick once over and make sure everything is in place. and the truck starts up no problem on the 2nd try. Any thoughts?