take a jumper wire ground . frame to bulb socket while some one steps on breaks. when you step on breaks or turn signal on do parking lights dim if so you have a bad ground.
sounds like it maybe a bad ground. take jumper cable from battery ground to agood ground on engine. their is also aground strap from the back of engine to the body. good luck
sounds like air . have some one step one gas alittle and add coolant and put the cap back on . also make shur your heater is on to get that air out as well.
remove radiator cap .start engine let run til warm .have someone step on gas a little.this causes antifreeze to go to heater core.thats why you get heat when you drive.you will see ratiator will be low add antifreeze while steping on gas petal . then put cap back on. you will have heat now:Dinjoy
did you change the tempture sensor at thermstat . it changes your gas air mix in colder temps and have all codes erased or it takes about 75 warm ups from cold