How to adjust the brake parking cable on a 2008 mercedes benz gl450

Question edited for clarity, full year make model.
Question moved to Category.

Fuses and relays.

https://www.google.com/search?q=2007+mercedes+benz+GL450+fuse+box+diagram

A/C issues

https://www.google.com/search?q=2007+mercedes+benz+GL450+AC+compressor+issues

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check for loose connections or wire grounding out near the park brake switch
as it should be air controlled spring brakes for the park brakes check for a problem air switch in the park brake air lines

Hi ARTHUR,HERE'S A LINK ON YOUR e-BRAKE. Pelican Mercedes Benz Tech Article Adjusting Your Mercedes Benz Parking...

Most charts can be found printed on inside of fuse box cover. Red.

you can go to the benz world org forum and ask

Unfortunately, you vehicle has 3 different fuse panels. If you look under your rear cargo deck (where the tool kit is), you will hopefully find a "fuse map". I believe the tail lamp fuse should be in the rear fuse panel.
I'm not sure where you live, but in Canada there is also a campaign to replace the tail/brake lamp sockets.

over 80% of mercedes ever made are still on the road in use,only volvo can beat this fact with over 90%.
keep it serviced at 10k intervals,and it should last 30 plus years.
bodywork is galvanised,so look after paintwork(1 dent/scratch will knock over $1000 off the price...)only buy if full leather and keep it fed.

You have permanent all wheel drive dude. The system is always ready to go. If you want to do some offroading, activate the "off road" button that looks like a vehicle climbing uphill on the lower, center dash panel. This will allow more slip for the traction control system and hold lower gears longer in the trans