Put the battery in wrong -and + put it back the right way now horn front windows won't and heated seats inopertive what steps do I go through to correct the problem on a2008 C-300
what in the world is C300, a Mercedes? yes,? or Chrysler 300? nah.wrong forum. so i moved you.engine run?head lamps work?you blew fuse.,find them and replace them.if lucky, hope you did not blow up electronics, this no 1970 jeep.most electronics have a polarity diode protectivedevice inside, just this error.but not all do.can happen easy with dead battery and jumper cables backwards too.some electronics use a clamp device (called a zener)that turns on and blows the fuses. on reversal.i've repaired many and even lightning damage horrors.Most alternators have same thing, and can blow the huge fuse link that goes to same.boom,steps:?1: put the battery back correctly Plus to plus.2: check all fuses. if they look blown they are,if the look ok we test them.there are only 2 ways, ohms 0= goodohms infinity bad.or volts.key on all fuses 12vdc both sides, (rare exceptions)google how to check fuses.same for 100 years.one more , the alternator will not like reversals.the main diodes may turn on , and blow the hugeALTERNATOR LINK fuse.as seen herehttp://jeepdied.com/chargelampon.htmlif this link blows, the car will start, but the battery will go dead in 1hr or less driven.the dash voltmeter will show 12v and falling.