PLEASE NEED HELP DESPERATELY! BATTERY CHARGING ISSUES

[Gavin]

Hello all. I recently replaced my battery on my 07 pt cruiser. I am embarrassed to say that I connected the positive and negative terminals incorrectly. I blew some fuses in the process but more importantly, my battery light now stays on. My battery will only last for a few hours before it dies.

I tested and replaced accordingly, all of the 10V, 15V, 20V, and 25V fuses. They all work properly now.

I took the battery back to where I purchased it and had them test it. The battery tested good and they told me it was my alternator. So i took my car to the dealership where it is under warranty for the alternator replacement.

2 days later, after replacing the alternator, the dealership tells me that it isnt my alternator and that it is most likey the PCM. The mechanic tells me that in order to do The PCM replacement that they first had to replace my battery harness, which would cost over $300 in parts and labor!!

I am almost 100% positive that it isn't the harness. Yes, there is some corrosion, but I never had this problem prior to installing the new battery. I never had any battery light come on prior to the new battery installation either. I believe that there was some fuse blown that somehow powers the alternator or its a fuse that is draining my battery power.

I am tired of "mechanics" giving me the most likely, technically sound response for what they think the problem is. First it was a "bad battery", then it was a "bad alternator", now its probably the "battery harness", and if that doesn't work then it must be "the PCM". Could it simply just be some a simple fuse issue?

I already know that when they replace the battery harness that I will still have these issues! They want to charge me over $300 to replace something that cost under $50.

Does anyone have any ideas as to why my car is running strictly off of the battery? These issues were never occurring prior to the battery installation. Only after the positive and negative terminals were connected did these issues occur.

Any help is GREATLY appreciated. Thank you for any response on this frustrating matter.

[Carl48]

When you reversed battery polarity you forward biased the alternator diodes. The harness carried the current but if it doesn't look physically damaged it is probably OK.

Before the dealer randomly replaces any more expensive parts, look at the fusible link...it is a dark green wire that runs between the starter motor and the alternator. This fusible link carried the full short circuit current during reverse polarity and may very well be burnt open in which case the alternator will not charge the battery. Check this out before doing any thing else. Hopefully it is just an open fusible link and not the PCM or TIPM.

[Gavin]

Carl, thanks for that info. That clears up a lot of questions that I had.

[Gavin]

Just how difficult and costly is it to replace the PCM panel anyways?

[randyincctx]

Unlike older cars that had a seperate voltage regulator;The PT Cruiser utilizes an Electronic Voltage Regulator (EVR),which is not a separate component.
It is actually a voltage regulating 'circuit' located within the Powertrain Control Module (PCM),the EVR is not serviced separately.
If replacement is necessary,the PCM must be replaced.....Some can be found from online sellers for about $125+(incl. re-progamming).

[pain442]

you can buy an external voltage meter to repalce the one in the pcm you may have fried fro 56$ compared to the pcm price

[pt06]

Gavin; the large stud on the alternator can be used to test the fusible link that Carl suggested. It should always be 12v. A test light will tell you that it is not totally burned out, but a larger load [like running thru an old headlight] tells you it's ok.

Just to complicate matters, there is another fusible link inside the harness that goes from the alternator to the pcm. This is for a 2006, and likely the same for yours.