hey scotty, i have a 2008 pontiac g6 gt 3.5 sedan and i have an electric issue. my tail lights fuse keeps blowing up and the mechanic couldn't find the problem and gave up. the fuse only blows in 3 min, what you think it may be or what you recommend me?
You may want to start by pulling out that Parking Lamp relay (it's right next to that fuse that keeps frying) and examining the sockets where it plugs into the fuse box. Look for corrosion or evidence of overheating. If it looks good try swapping another relay in its place and seeing if the issue clears up. It looks like the backup light relay is in that box. Borrow it.
If the fuse blows again the easiest way to narrow down where the problem is may be to just unplug each light harness one at a time until the fuse doesn't blow, and then investigate that light, its sockets, and its wires.
You have connectors for each of the tail light/side marker lights in the rear and for each front parking light/side marker light.
Don't forget the license plate light. (it's not shown in the diagram)
CLICK IMAGE TO ENLARGE
but the tail light fuse is also connected to other lights components for example the climate change lights, the steering wheel control lights and control windows which would mean i would need to disconnect a lot of connecters
You won't get any argument from me that chasing down electrical issues is time consuming.
Yours is even more difficult because the fuse takes 3 minutes to fry after you turn on the parking lights.
Looking at the diagram it appears that the HVAC control module and the BCM receive a 12 volt signal when you turn on the parking lights and they're likely controlling that interior illumination.
The fuse is blowing because too much amperage is flowing through it.
Why would that happen? Corrosion/short.
In this circuit the most likely place for it to happen is with the exterior wiring/lamp sockets.
So, like I said, after examining the relay, the easiest way to narrow it down may be to unplug each individual lighting harness one at a time.
You don't want to unplug everything on that fuse's circuit all at once. Like I suggested, because all 4 corners of your parking lamps with their side markers can individually be removed from the circuit by disconnecting their connectors, it may be the easiest way to begin your troubleshooting.
The connectors are easy to get to and the harnesses are available (even cheap aftermarket ones) if you determine that one of them is causing the problem.
So, your fuse blows in 3 minutes, You'd unplug one at a time. Let's say you begin with the right rear. Unplug it. Let the car idle for 10 minutes with the parking lights on.
If the fuse blows, reconnect that harness and move to the left rear and repeat. Then the license plate light. Then the right front. Then the left front.
Chasing down wiring issues takes patience. I wouldn't worry about "what ifs" until you've ruled out the exterior light sockets and their wiring.
..... just submitted for your consideration