Hooked up cables wrong on my sl600 mercedes and now it will not .

If the 6 volt batteries are wired neg to pos to neg to pos to neg etc, then do the same with tha 12 volt batteries. So neg on one to pos on the next, then neg on that one to pos on the third. (- +) (- +) (- +)
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Sounds like someone has changed the starter recently and they have the negative cable from the battery hooked up to the starter solenoid. You need to have the positive cable hooked to the starter solenoid not the negative cable.

If the battery is good you will need to follow flow. Test light is the easiest to use. First hook light to ground and touch pos terminal,lights good next touch pos battery cable end, lights good. Next follow pos cable to starter pos terminal,lights good. Next hook test light to bat pos teminal,touch neg terminal,lights good. Then touch engine block, lights good ground. Next move test light clamp back to ground/neg side and touch alt pos terminal,lights good.if all that tests good, if all good move inside and check for power at ign switch pos term if at any time you dont find power you have wiring issue that needs to be addressed. Let me know what you find. Russ

Almost all car batteries have 2 pos and 2 neg. More precisely, 1 pos post and 1 side connector, 1 neg post and 1 neg side connector. You only usually use use one set or the other depending on what connectors are on the end of your cables. You can connect something else to the side posts if you need to, but generally only pair is used.

You will have to take it to the Dealer. You may have burnt out or the "Control Module" needs to be replaced or reprogrammed. Make sure the battery has not reversed polarity also.

Bad connection on cable ends or where they connect to battery. Quick check is if you have a good set of jumper cables, use the jumper cable as a replacement for what maybe the defective one. Hook negative cable good to battery neg. post and then put other side on neg cable to engine ground on block. See if it cranks, if it does than the trouble is on the neg. cable. If not then put positive cable on pos. post of battery. Then put other side of pos. cable on the starter post, try to start. If it cranks then the trouble is on the pos side of cable. Hope this helps.

so let me ask...you have one end hooked up to the neg. on the battery,and are wondering where to connect the end that grounds to the engine?as you know the battery needs both pos. and neg. to be able to allow voltage to pass thru.is your question .where does the other end go?

only if you hook them the cables up wrong. Always mak sure you have pos side cable from your car to pos to the other car and neg to neg.

Make sure starter end of battery cable is not touching anything else but the mounting post on the starter. Make sure Pos is to pos and neg is to neg

hook them up in parallel, pos to pos, neg to neg from one battery to another, then pos cable to battery prs and ground cable to neg battery