Mysterious 12V Accessory Jack Problems

I have a strange problem with my 12V accessory plug in my 2001 Chevy Cavalier.

The Problem: When I plug in my iPhone Charger, the light on the device comes on (indicating power), however my phone does not charge.

What I have tried:

I’ve checked the cable, it’s good (works in my wife’s car)
I’ve checked my phone and it is not the problem (charges fine in other cars)
I’ve tested the jack with a multimeter - gets 11+V Car off, ~12V car on
I’ve tested the polarity of the jack, the positive is in the center, negative on the outside

Possible related causes:

The jack and charger worked fine at first. When I noticed it not working - I had to replace a blown fuse.

I used the same amp fuse as the old one, the new one has a light that illuminates if it breaks again.

This led me to wonder if a car I recently had jump-started from my car/battery caused the blown fuse (likely)

Also I have been having some starter issues and recently had it replaced.

I’m stumped as to what is causing my charger to come on, but not charge my phone. Could the power from the jack be “dirty” or insufficient in some way?

You should be reading 12+ volts with the ignition off. Have you checked the voltage at the battery?

And you should be reading around 14 volts with the car running. If you used your car to jump start another car and something went wrong (reverse polarity, etc.) the problem probably would have manifested itself in more sensitive parts of the car’s electrical system than the power outlet.

I wonder if there is corrosion in the accessory socket. The corrosion may drop the voltage enough to prevent your iphone from charging, but allow the led indicator to illuminate. I would pull the fuse for the accessory socket and insert the blade of a small knife and scrape the center contact. You might then follow up with some electronic contact cleaner.

Checked the battery (at the battery) and was getting 12.5V off and 14V with it running.

I will check the socket for corrosion. It didn’t appear corroded but you never know. I’ll clean it (with the fuse out!) and get back with the results.

Plug a lighter in it and see if it heats up…If the lighter glows, the charger should work…

If you’re getting 12.5/14 at the battery (good) but only 11/12 at the jack then I’d second cleaning the contacts.

FWIW I have an iPhone 4 and a Belkin car charger. It works fine in my vehicle with the engine stopped (12-12.5 V). It stops charging (beeps like you unplugged it) when I crank the engine but it’s because power does not flow to my lighter socket when I’m cranking–so I can’t confirm whether or not my phone will charge at a lower voltage.

Err, worded that backwards…phone loses power on cranking and beeps when it starts re-receiving a charge when my vehicle starts. Same difference…