Lots of panel lights then nothing

KRISTIW7

MEMBER
2008 ACURA TL
3.2L
V6
2WD
AUTOMATIC
108,000 MILES

Something was humming when I left this morning. Did okay there. About halfway home, I noticed the battery light on, and at the light it hesitated accelerating. The lights started coming on one by one. I turned off everything extra I could turn off. The radio, air, even my windshield wipers. It was raining. Then the lights stopped one by one and the dash panel went black. It was barely limping along. Would only accelerate to about twenty five mph. That is a guess since no panel. Finally got in the driveway. It would not shift into park. Shut off. Was then able to shift into park and I put on e-brake. Next day I went out to look and the panel came on and it acted like it might start, but would not turn over due to not enough power. My husband thinks it might be that the serpentine belt tension-er has gone bad. Any thoughts? I hate to replace the wrong part. I just replaces the battery about a month ago. Menke's Auto Repair had also told me I might have an electrical short. I had not had a chance to take it to an electrical place before this happened.

3 Replies

CARADIODOC

MECHANIC
33,742 POSTS

This is a very common description of a failed generator. The entire electrical system has to run on the battery until it slowly runs down. Beginning with a good, fully-charged battery, the most you will get with the head lights and wipers on is about an hour. A half hour is more realistic.

https://www.2carpros.com/articles/how-to-check-a-car-alternator

If the belt or tension-er were the cause of the problem, you would have heard an intermittent squeal, and you would have lost power steering. Use a portable charger to charge the battery at a slow rate for about two hours, then have your mechanic perform a charging system test. You can do the first step yourself with a digital voltmeter. Measure the battery voltage with the engine running. It must be between 13.75 and 14.75 volts. If it is okay, that only means it is okay to do the rest of the tests, but that requires a professional load tester. If it is low, the generator is the best suspect.