1998 SLK 230 automatic with 117,000 miles.
All warning lights come on when the key is turned to position 1. A week ago, the charging warning light came on. While the car was running, my voltmeter showed only battery voltage. I pulled the voltage regulator; brushes were short but almost the same length. I replaced the voltage regulator. The light went out. Voltage from the positive cable to chassis ground was 13.88v. Two days later, the warning light became intermittent. However, it is always off right after the car starts. My voltage meter still shows 13.88v. Auto Zone tested it and said that the alternator was fine and was charging at 13.99v. I cleaned as many grounds as I could find without making a difference. A rebuilder near me said that he didn’t recall intermittent faults with alternators, but that I could bring it to him and he could check the diodes on his oscilloscope.
Does anyone have any thoughts? I hate to take it out if I don’t need to.
All warning lights come on when the key is turned to position 1. A week ago, the charging warning light came on. While the car was running, my voltmeter showed only battery voltage. I pulled the voltage regulator; brushes were short but almost the same length. I replaced the voltage regulator. The light went out. Voltage from the positive cable to chassis ground was 13.88v. Two days later, the warning light became intermittent. However, it is always off right after the car starts. My voltage meter still shows 13.88v. Auto Zone tested it and said that the alternator was fine and was charging at 13.99v. I cleaned as many grounds as I could find without making a difference. A rebuilder near me said that he didn’t recall intermittent faults with alternators, but that I could bring it to him and he could check the diodes on his oscilloscope.
Does anyone have any thoughts? I hate to take it out if I don’t need to.