i bought her, now whats wrong??

Read post 11 again. If it's the ignition switch then it will either go open circuit (no volts through the switch) or increased resistance across the contacts (reduced volts across the switch). Hence measure the output which is a quick easy location to get to. If the switch is failing then it will be brunt contacts. You'll see burnt bits of carbon deposit on the contacts. There's several contacts on the ignition switch. You won't solve the problem with switch cleaner. It's new switch time if that's the fault. I used sand paper to clean my contacts and it worked for a while but failed again. A code reader may give a code. It could be a simple sensor giving a sudden bad reading which shuts down the engine. The computers normally stop at something like 9 volts. An easy test is to measure the lighter socket with the engine running, then load the ignition switch further by putting all the lights on and measuring again. You may have a loose fuse in the engine bay fuse box. Could be the connections to the ignition switch. I wouldn't expect your battery to have a loose connection as the cause as the alternator will still power the car once the engines running.