Tail light/marker/dashboard light fuse keeps blowing. I read somewhere that the harness for the front driver side marker could be grounding on a screw. If this is the problem, how do I remover the front marker light assembly to check the harness and if this isn't the problem, any suggestions?

Check the tail light bulbs & marker light bulbs.

What about them ? What front lights ? Headlamps , park lamps, marker lamps ? They don't work ?

Exterior Lamps
The exterior lighting system consist of the following lamps:
• The Headlamps
• The Daytime Running Lamps (DRL)
• The Clearance Lamps (Y92 roof rack only)
• The Cornering Lamps
• The Front Fog Lamps
• The Rear Fog Lamps (Export)
• The Park, Tail and Marker Lamps
• The Turn Signal Lamps
• The Stop Lamps
• The Backup Lamps

Park, Tail, Marker, License, and Clearance Lamps
The park, tail, marker, license, and clearance (Y92 only) lamps are turned on when the headlamp switch is placed in the PARK or ON position or anytime the headlights are requested. The I/P BATT fuse in the engine wiring harness junction block supplies battery positive voltage to both the park lamp relay switch contacts and the park lamp coil circuit. The body control module (BCM) provides a ground or control circuit to the park lamp relay coil circuit. When the park lamps are turned on, the BCM energizes the park lamp relay. Current flow is from the park lamp relay to the individual park lamp circuit fuses and to their respective park, tail, marker, and license lamps. The front park and marker lamps are grounded at G107 and G103. The tail lamps are grounded at G401 and G402. The license lamps are grounded at G401. When equipped with the Y92 roof rack option, the clearance lamps are grounded at G302. If the driver places the headlight switch in the ON position after the ignition switch has been turned OFF, the park, tail, marker, license, and clearance lamps will remain on until turned off or the battery runs dead.
The T PARK fuse in the rear fuse-relay block supplies battery positive voltage to a separate park lamp circuit connected to the trailer wiring harness.

Park, Tail, Marker, and License Lamps
The PARK/LAMP fuse in the instrument panel (I/P) fuse block supplies battery positive voltage to both the coil and switch sides of the PRK LAMP relay, also located in the I/P fuse block. When the headlamp switch is placed in either the PARK or HEAD position, ground is supplied to the BCM on the park lamp switch ON signal circuit. The BCM then applies a ground to the park lamp relay control circuit. This energizes the relay, applying voltage to all park, tail, marker, and license lamps. The park, tail, marker, and license lamps are also turned ON when the headlamps are commanded ON by the BCM for low light operation.
Ground for the headlamp switch is from G200. Grounds for the various lamps are as follows:
• G100 supplies the right front lamps
• G101 supplies the left front lamps
• G400 supplies the right rear lamps
• G401 supplies the left rear lamps

That's very odd, because the wiring for all of the side markers are just splices from the nearest park lamp wires- the rear tail light in the rear (and the license plate lamps are also splices from these tail lights), and in the front side markers, they are splices from the nearest park lamps. Do all the other park lights work and turn on with the park light switch on? I would examine the 2 wires from that side marker's socket to the wiring harness it goes into-the power wire would somewhere splice into the passenger tail light wire. The other wire would be a ground wire and also splices into a ground wire for the rear end. To be on, the marker lamp would have to be getting power from some live source. I can't imagine where. Does the rear passenger light work correctly?

In that harness to the rear where the park lamps run, there might be a live wire going to an electrical trunk latch switch, or maybe a trunk lamp. If the wires were frayed right beside the side marker wire, you could have some cross feeding of power between the two. Let me know, we always appreciate feedback.

If you confirm the side marker lights,tail lights,fog lights and/or dash illumination are inop,and fuse number 39 is open,the wire harness is chafed/damaged at either the left or right front side marker lights....Removed both front side marker light and repair the harness wil fix your problem.....Let me know if you find any damaged wire harness

use a light circuit breaker in place of the fuse, then check harness for short to ground, start with tail light harness, or trailer wiring if so equiped

Hello, the 15A tail fuse is the only fuse in this circuit, yes there is a short to ground, remove all the bulbs in the rear and check to see if the fuse still blows, if not the problem is at the rear lights, possibly a wrong bulb in one of the sockets or s short between the green wires(power) and ground(white/black) wires. If this doesn't stop the short then the problem is up front, possibly a parking or side marker light, do the same, remove the bulbs, if the fuse stays in replace the bulbs one by one until it blows again to isolate which light is causing the problem.

do you have a tow hitch? if so start at the wiring for the tow package usually corrode and short out the lights. if you don't have tow package harness at the back then i would be looking at the front side marker light wiring, if dash lights are effected it means problem is in the park lights only.

you have a short somewhere, unplug the tail lamps one at a time and see if the fuse still blows. if you disconnect one and the fuse does not blow and everything else works, the problem is in the tail light assembly. if not, the short is most likely in the wiring harness which can be a bit tricky to diagnose. alldata.com/diy offers one year subscriptions to cars with all the repair info and they have excellent wiring schematics. dont forget to try the front marker lamps in addition to the tail lamps.

Took it to the shop. The side marker lights were missing on my son's car. The wiring loops from the side marker lights to the tail lights. As the wires were touching in the front, they shorted out the tail lights. Capped the wires, problem solved!
PS: ordered side marker lights, too.