Dumb question about fuse box HELP !!!
 

I recently got my car back from the shop and the brake lights no longer work. I have tried to open the fuse box under the hood to check fuses. However, I can't seem to get the box open. Both knobs turn about a quarter of an inch and that is it. What do i need to do to get the cover off the box?? Also, any other suggestions about the brake lights. All other lights still work, hazards, turn signals, and headlamps. I cant seem to find anything else wrong. The shop just changed fluids and worked a little on a vacuum problem. I am relatively new to the mbs and am still getting my feet wet. Any help is much appreciated.
car is a 1978 300D electric windows still work as well

thanks

the knobs should unscrew and then just turn in place where you can pull em out.. then its a work of art getting the cover out.. i cannot describe how to do it but dont yank hard..

uggh
 

The nobs turn and turn, no end in sight, and they dont pull out any or pop out. What am I doing wrong? any chance they are corroded inside?? Have to break the cover off??

Once you have the screws loose, it can be fun trying to get the cover off...as they built the fuse box first then built the car around it....takes some work, but just pull on the two screws...you should be able to get it off after a few tries....then of course, you have to get it back on...that will probably take a while longer....

Best of luck!

It sounds to me like you...
 

have successfully loosened the thumb screws and the cover/lid is still held on by the soft gasket that is stuck both to the lid and firewall. This is probably because the last person who installed the cover over-tightened it. So when you do eventually remove it, don't make the same mistake when reinstalling!

With the screws loose, I would spray some WD40 around the perimeter and then try to gently twist the lid/cover right/left until the soft gasket pops loose. Then it's a matter of rotating it to clear other nearby components such as brake booster etc.

Once you get inside the box, I know that these cars often have the tail lights on 2 separate fuses. I'm not sure about the brake lights and I'm away on a trip so I canNOT check... but when you get into the box, you should have a paper card inside the cover/lid that lists the fuses/applications. Read all of these just in case there are 2 fuses on the brakes as well.

Let us know how things go !

Sam

problem solved
 

well thanks for all the help and advice. Problem was the screws has rusted/fused with the part they were screwed into. Soooo.....no unscrewing them. With the help of my trusty hacksaw, and some serious patience, so as not to cut anything else, the screws are removed and Im into my fuse box. Will update when I get some fuses changed, and see if it fixes the brake issue. I really hope it does.

thanks again,