Chrysler Repair: no start after hooking up battery charger wrong, chrysler sebring, diagnostic capability

Question
Hi, my neighbor went to charge the battery on his 96'ish chrysler sebring convertable. he realized after a few minutes that he had the charger on backwards. He reconnected correctly, charged overnite. Now the car will no start. Cranks fine but appears to be no spark. What blew when he hooked up charger wrong? Fuse, relay fusible link??? Also any help with location of fuse to check would be great.  Thanks Mike

Answer
Hi Mike,
If it is a '96 it should have self-diagnostic capability that is accessible via the ignition key:"on-off-on-off-on and leave on" doing that in 5 seconds or less elapsed time. Then watch the 'check engine' light, which remains 'on', to begin to flash, pause, flash, etc. Count the flashes before each pause. Then repeat to assure an accurate set of counts. Then combine the counts in pairs in the order of appearance to form the two-digit fault codes. The last will always be 55 which is the code for 'end of readout'. Then write back with the numbers or go to www.allpar.com/fix/codes.html for a translation.
The fuses between 1 and 10 in the power box under the hood are all going to be potentially at risk from a reverse voltage, so look at all of those (7 may not be in use). Fuse 5 powers the engine computer so pay special attention to that one in case it has a subtle crack instead of being blown. There are no fusible links in the system.
Roland