Tang 72

So my 07 GT has some interesting power issues. Occasionally the car will say to check the charging system and the A/C and radio will turn off and restart. The car itself never turns off, lights and everything else stays on just as before. I originally thought alternator but when you run the regular system check it says its fine and when i used a voltage meter its putting out about 13.8 volts while under charge, the car also runs fine if i take the battery out of it. The battery is not very good so i switched it with another battery from one of my other cars and its doing the same thing. I am wondering if it could be a bad relay but i don't know of any relay that controls the A/C and the radio together. Has anyone else seen this before?

Nuke

Based on your description I still have to think alternator. My 2nd guess would be that you have the water leak issue and your SJB connections are beginning to corrode enough to cause intermittent contact. Does this tend to happen more when it has rained or is very humid out? If so, then my 2nd guess becomes my 1st.

Lifter583

I am with Nuke...new alternator...brushes going out...had a friend just have the same thing and changed the alternator and all is well....

Tang 72

Yea that could be the issue. I took it down to advance to see if they knew anything i didnt, they also said the alternator was fine, could not find any issues. Keep in mind it is only the AC and radio that turn off and back on, everything else is fine. IDK though i might replace it anyway, im at 93k miles.

wcgman

Im with nuke alternator...

Art161

Don't do this! The battery acts as a capacitor and prevents voltage spikes from frying your electronics. This may not show up immediately, but you are risking future issues.

Derf00

Yeah...never disconnect the battery with the car running. You could do this with older cars (pre electronic ignition) and get away with it, but newer cars with all the electronics could be damaged by doing this. At the very least you risk damaging the alternator, at the worst, you fry your PCM.

The Alien

I quote Nuke too, Alternator.

even if the voltmeter reads 14.0V you can't test the load, you have tension, volts, but you may not have intensity, Ampere.

depending of the damage, brush or regulator, you could have the situation get worse rapidly, if it's the regulator, you could have on the future consequences also on the battery.

Nuke

And not to belabor the issue, the alternators in the S197 are mediocre at best and often test fine at autoparts stores and even at the dealership but those that replace them anyway say that their problems were solved.