1973 450 sl------won't start
 

I got a jump start the other day which is the ghost of trouble. My neighbor connect the postive cable to the engine block. Not only did I not get a boost.,the battery cables melted right on the car.
Now the car won't start even with the proper jump start. What damage have I done and how to fix it. thanks

Good grief. Lucky you didn't have a battery explode. Start thinking in terms of fried wires. If you did not have your key on, most of your electrics will probably be ok. Big damage will be at the battery (at least swap it out for testing) and any cables that were in line in the short. Don't forget to check frame to engine ground cables. You may have to replace several wires and cables. With new battery and any bad cables you can see replaced, try putting a meter on the starter and see if you have 12 volts measured between the case of the starter and the big battery cable stud. Turn key and see if voltage stays there or if it drops to new zero. Also, see if you get 12 volts at the small terminal when you turn the key. After that, you are going to need the wiring diagram. Side note: when you install the new battery, try to measure any current draw on the battery with everything turned off. Anything more than say 0.03 amp is probably a componet gone south.