My fuse blows when I turn on my parking lights

check to see if the release of the parking brake actually engages the warning light switch fully.

trailers are add on package , 1st just inspect the fuses with a flashlight . as you should once a year.
http://www.tundrasolutions.com/forums/tundra/193937-blowing-tow-light-fuse/
lots of good answers here

Could be the park lock solenoid. Thats the part that locks the shifter in park and requires you to press on the brake pedal to release.

Park, Tail, Marker Lamps, and License
The park, tail and marker lamps, including the license lamps, turn on when the headlamp switch is placed in either the PARK or the HEAD position, or anytime the headlamps are requested. The RT I/P #1 fuse in the RH I/P fuse block supplies battery positive voltage to both the park lamp relay switch contacts and to the park lamp relay coil circuit. The park lamp relay coil is controlled by the body control module (BCM). When the headlamp switch is placed in the PARK position, the BCM energizes the park lamp relay coil control circuit.
Current flows from the park lamp relay switch to both front and rear park lamp fuses and to their respective park/tail lamps. The front park lamps are grounded at G101. The rear park lamps are grounded at G302. The license plate lamps are a part of the rear park lamp circuit and are grounded at G302. The inadvertent power control feature prevents the park lamps from remaining on more than 10 minutes if left on. If the park lamps are turned on after the ignition switch has been turned OFF, or is in the ACCY position, they will remain on until turned off or until the battery runs dead.

Did you the REAR PARK LP fuse 15 amp in the right insturment panel fuse box.

see if you have a shift lock release, usually you step on the brake and you can shift out of park when the truck is running

Check the fuses. I do believe there is a left and right side fuse for the headlamps. For some reason toyotas, especially highlanders, like to blow the fuses when the headlights burn out.

I’m happy to assist further over the phone at https://www.6ya.com/expert/jeremy_d728a59f986299fa

Hello.

We would suggest that you look at the wiring connector under the bed, that feeds the taillamps.

You will probably find a coroded wire in the connector. If the 3rd brake lamp works, all of the fuses and switches are good.

Normally, an burened out brake light fuse will prevent the shifter from coming out of park. A bad brake pedal switch that activates the brake lamps could also cause this issue. A more remote cause would be a shorted out trailer harness, that is causing the brake light fuse to blow.

YES -- process of elimination. Obviously there's a short circuit in the Brake/Headlight circuits - right? Blown fuse(s) is/are evident of this -- would you agree? Which fuse(s) is/are blowing? An analysis tells you that the only time a fuse blows is when the headlamps are turned on -- correct? Otherwise, brake lights work normally -- right? OK. Head lamps have relays which turn them on. Here's a wiring diagram of the 2000 Hyundai Sonata (NOT the Jeep Grand Cherokee)
It would appear the problem is with one or more bulbs or sockets or both. As you many notice, there are no connections between the headlamps and brake lamps except the parking lamps (which share the bulbs/sockets)
When the headlamps are turned on, so does the tail lamp relay. As you can see, these bulbs/sockets are 'DUAL' filament to ground (series-parallel circuit). Just a guess here - the short is in one of the lower rear brake/parking lamp bulbs/sockets.... just a guess.

Hi my Name is Marcus . I have a 99 toyota corolla and i have problems with the brake lights . I have change the bulbs . I have check my fuses , i have also change the brake pad switch . I was told that i to change the brake switch with a part for Toyota Dealership . Plz help me