1983 380 SL trunk problems/battery problems
 

My wife has an 83 380 SL and the battery is dead. I tried to open the trunk to jump it off but the trunk won't open no matter what I do.

Does anyone know what can be done to break into the trunk without causing much damage or how I can jump this thing off without being able to get to the battery?

Thanks in advance for the help.

Try this first:

With the key in, turn the key to the left and press in. This worked for me when I screwed up the linkage.

Failing that, assuming that you can get in the car, I'd charge the battery with a trickle charger in the lighter socket, but it will take some time (like, a day, probably).

I thought about a trickle charger with the cig lighter...but how do I know the poz from the neg wire?

And for some reason the trunk just won't open...no matter how I turn the key or push the button.

You can buy chargers made to do this; but search this forum for instructions on where to jump the car under the hood - I think I've seen it somewhere.

under hood battery terminal
 

The 560SL has a positive battery terminal under the hood that can be used for jump starting. It is located under a snap-off cover on the passenger side inner fender. The positive cable attaches there and the negative to any good ground point.

Hope the 380SL is configured the same.

I've been following this post and I've had the same problem with the trunk not opening. For some reason, I've been lucky and after several attempts, it's suddenly opened. But I am very interested in finding out if you can jump or charge a 380 from under the hood. I did a search, but came up with nothing. If someone out there knows a jumping point under the hood, please post it. I'd also like to use the hot location for using a timing light when tuning the engine.

Positive terminal
 

On my '77 450sl there is a positive terminal block on the passenger side fender near the expansion tank. I had to pull it apart and clean it once to get the battery to charge at all. You do have to pop open the cover to find the large post underneath it.

This morning I went out and the trunk popped right open. This car is driving me crazy. I think I found the place on the fender to jump the car off from...its a black box with a plus sign on the top and mine has 2 cables bolted to it. One is thicker than the other. Does this sound like it? How would you jump off using this? pos on the bolt the cable is mounted to and the neg on sheet metal under the hood?

Thanks again.

battery contact
 

for Badkarma: Correct. positive to the point you have identified and negative to any good ground point. I suggest engine block or chassis rather than hood. Look for a point with no paint, just bare metal.

It would be interesting to know why this is happening. I thought that if you could turn the key to the left, you would be able to push the button in and unlock the trunk, regardless of the position of vacuum lock.

Are you using a master (square) key and not the valet (round) one?

jump starting sl's 107 series
 

It is a shame that the mercedes instruction manuals do not show how to jump start these models. As you hopefully are aware, under the hood on the passenger side near the coolant bottle is a plastic cover marked with plus (positive) mark. Lift this to expose positive bolt. This and lift tab on engine (for negative) makes emergency jump start easy as well as charging, testing, etc. It is something that some owners are not aware of and should be. Good luck Abe G

I'm pretty familiar with the mechanism and I think that this should have worked also.

The trunk lock mechanism gets worn or messed up and that won't work any more. I'm still trying to get it to work on one of mine. I've taken the lock apart, I know what's going on, I just haven't seen the way to fix it yet.

One thing to remember is you MUST turn the key counterclockwise BEFORE you push in on the button so the cylinder arm will connect with the lock mechanism. If you push in and then turn counterclockwise nothing will happen.