Rear end is poping when i make left turns. - 2003 Ford Explorer

have the front end checked
indicates a problem in the tie rod ball joints or steering box

not normally the controll unit yes and the poped air bags but the rest will be ok the controll unit stores any accidents and will have to be replaced it cannot be reset

it can be your parking brake shoe in the rear that is inside the rear rotor. there is a brake pad and a parking brake shoe in the rear

depends on where you hear the noise.. could be a brake caliper sticking or a universal joint going out or has went out in the drive shaft. while driving does it make the noise constantly or just when taking off?

What year? Sounds like a bad u-joint or cv shaft if it is newer that 88

You need to replace the rear temp control actuator.

Loud popping/grinding most noticeably heard when turning is normally a sign of a bad CV joint. Look under the van where the axle half-shafts come out of the transaxle and connect to the backside of the wheel assembly. Are the rubber boots on the axles torn or missing?
If you hear the popping only in left turns, your right CV joint is bad, If you hear the popping only in right turns, your left CV joint is bad.

cv joints

If it is more of a poping sound coming from the front end, then it is probably a cv joint

IF YOU ARE TURNING HARD THEN GREASE YOUR STEERING STOPS
you will see a wear mark on the knuckle and lower control arm just wipe some grease on these spots