This happens when one of your 1157 bulbs is installed BACKWARDS.
The bulb could be in any one of the four corner positions.
Left Front, Right Front, Right Rear, Left Rear.
You have to take out the bulbs and note the positions of the barbs on the bulb base
in relationship to the locations of the wires on the bulb socket.
When you find one that is reversed, that is the bulb that is causing the fuse to blow.
It has been my experience that when the blinker comes on but the lights don't blink there is one or more bulbs burned out. If that is not the case check the flasher.
cheack the wireing
The tail lights are on a separate wiring than the blinker/brake lights. Look for a blown fuse or a broken/loose wire.
First check the fuse, or you may have a burnt out bulb
check the brakelight switch. it is located under the dash where the brake pedal rests. Hey its ritchie. If you can click your blinker down and then they work its you blinker switch,but this is my monte.
The GMC dash tail and parking lights are on a different fuse from the brake lights. Check the fuses for a possible blown fuse.
Daytime running lights can be turned off by removing the fuse that controls them. The fuse is in the passenger compartment fuse box. The fuse number is D5.
you have a short in the wires for your dash and lights So what do I do to fix it?
Your light has gone out or a bad fuse
Check the bulbs, check the fuse, check the flasher relay, in that order.
If parking lights and dash lights are not working and fuse blows out, there might be a problem with battery corrosion. Check the components specific to the circuits of the affected lights. It might be loose.
Probably the Tail light fuse is blown. You also lose dash lights when this fuse blows also.