2009 e250 keeps blowing 10 amp parking fuse then

Why do fuse's keep blowing ? A short circuit to (ground) somewhere . Do you know how to use a wiring diagram an a DVOM - digital volt ohm meter to test electrical circuit's ? Brake ? brake light's ? You can't get it out of park because of the shift lock solenoid ( shifter interlock system ) This is a safety system that won't let gear selector to move from park unless driver is pushing the brake pedal . The fuse blowing - no power to brake light switch , computer see's no signal so it won't energize the shift lock solenoid .
http://www.bbbind.com/free-tsb Enter vehicle info. Year , make , model an engine size . Under system click on lighting ,then under subsystem click on stop lamps . click the search button ,then the blue link.
Electric Testing Techniques You Need to Know
How to find short to ground blown fuse

of course changing a brake pedal switch will not help in a reversing light problem
they are two totally different circuits
check for a damaged wire at the reverse light switch or bulb holder for the reversing bulbs for a dead short
as for the rest check the IGN fuse under the bonnet

If the engine has started, the safety interlock is bad. (an electrical interlock. Or the linkages to the shift lever are bad, or the bushings on the linkage, or even problems with the shift lever pivot.

Question are you putting in the correct size fuse ? Look in the owners Manuel it will tell you what amp fuse goes where. May be as simple as that always make sure you put the same amp fuse back in very important.

I think your problem locating the fuse may be because Ford refers to the lights you are describing as "PARK" lamps, instead of "TAIL" lamps. The PARK fuse is Fuse #22 (15 Amp) located in the Smart Junction Box (SJB) in the center of the dash.

HINT: This same fuse also protects the circuits your front park lamps, if they are working, the fuse is not blown.

put a 12 volt light bulb in place of the fuse. It will stay lit until you find the short circuit. Check tail and park light & side marker bulbs first.

How about if you just turn parking lights on, not headligths

You will have to check the positive wire of the wires that go to the parking and side marker lights for a short to ground.Check the easy things first like the bulbs for these lights.It could just be a shorted bulb.You can remove one at a time and see when the fuse stops blowing.You an get a short finder from a part store and save the trouble of getting a bunch of fuses.Hope this helps.Good luck.

are you putting back the correct amp fuse.

check the earth on ur headunit it may be earthd to the rong thing

Could be brake light switch