I have a 2001 Kia Sportage Limited 4 cyl 4X4. It does the following: At night when I step on the brakes, the headlights dim.
Also lately while driving the radio will cut out and then come back on. Makes no difference what station it is on. And today when driving, I turned on the headlight and turned them back off and the car shuddered. The radio was on at this time and cut out also. PCM power relay was replaced on Dec. 8 2012. Any advice would be helpful. Thanks.
Have the charging system load-tested. I suspect you'll find the generator will only produce exactly one third if its design rating of about 90 amps. 30 amps is not enough to run the entire electrical system under all conditions.
The cause of the low output is one defective diode inside the generator. The fix would be a replacement generator.