2005 pt cruiser limited starting/battery issues

2005 pt cruiser limited when my daughter tries to start her car it seems she constantly has a “dead” battery. As soon as the starter engages her voltage for the batttery goes from 14 to 7.volt Is this a starter issue or an alternator issue. at one time the positive battery cable to the starter had been shorting to the starter. that was replaced. still having the same problem. Once upon a time (pre car computers) i would have suggested she have her voltage regulator checked. No clue on modern cars if it even has one. Or if all computer controlled.

Without knowing the age of the battery, the symptoms point to an old battery not holding a charge. How old is the battery? Are the cables/terminals clean?

Exactly where are you measuring 7 volts? Did you probe the actual battery terminals or the cable clamps? What is the voltage before you try to start the car? It should be about 12.6 volts.

If you probed the actual battery terminals, then you probably have a dead battery.

Start with a charging system test at a local mechanic or even an auto parts store. That will usually identify if the battery and alternator are good or bad.

Also make sure that the terminals are clean and tight. You might even look under the first inch of insulation, as sometimes corrosion happens under there over time.

Thanks guys, I did get a correction out of him, it is the amps which drops and I do not know where exactly he tested that. he did all the usual trouble shooting, turn this off, turn that off try again… And I agree, I think it must be in the battery, alt, or maybe the pcm ( computerized regulator or what ever they call it.) My son in law was thinking starter but I questioned that as if there is enough charge it will click, showing that the selenoid does engage. I will tell them to go to O’rielies or autozone and get the charging system checked out… By the way. This is one of my husbands favorite shows. He has listened to this show on PBS since he was a young man ( we being grandpas/grandmas now.) With all the computerization of cars. I wasin’t sure how much of what I new from my dad ( a mechanic he is passed in '87) still applied.
Will continue to watch for replies. Googling showed Chrystler cars seem to be real bad in electrical system issues in the early 2000 time frame, found everything from the ignition switch, pcm,. alt/ battery etc. They have quit uxing the key fob to start.stop lock car since that will set off the horn in the wrong way.

It’s unclear what tests exactly have been done. But for no-cranks, the first step is to clean the battery posts and connectors. If that doesn’t fix it, measure the voltage at the starter motor, terminal to starter case, at the two terminals. One is a thick wire, the other a thin wire. Both should be 10.5 volts or higher during attempted cranking (key in “start”). If they are and it doesn’t crank, replace the starter motor. If either is below 10.5 volts, work backwards toward the battery to find out why. If the battery itself (as measured directly on the posts) measures less than 10.5 volts during attempted cranking, that’s usually a battery problem. Recharging the battery with a battery charger to full charge, then doing a battery load test would be next.