Hey everyone,

I could use some advice on my 2012 Honda CR-V EX-L AWD with the 2.4L engine and entertainment system. Here’s the situation:

A few weeks ago, I had my car off but was listening to the radio for about an hour. When I tried to start it, the battery was dead and I couldn’t get it to jump. After charging the battery at home, it ran fine for a week until I noticed the headlights were dim. The following morning, the alternator started making a slight screeching noise, and I had dashboard lights flicker and lose power steering intermittently when driving at low speeds. After charging the battery again, I decided to replace the alternator.

I had the choice between a 105A Denso, or the NAPA 120A. I know Denso is recommended, but I thought 120 might’ve been what was used for the trim with the entertainment system. It was also more expensive, so my mind thought it must be better.

I picked up a NAPA remanufactured alternator ($288) and installed it yesterday. Everything started up fine, and the traction control and steering warning lights turned off after a couple of minutes. Wanting to confirm that the alternator was working, I took it to AutoZone for a test. Unfortunately, I received the results:

“BAD CHARGING SYSTEM”
Voltage Regulation: FAIL
Charging Current: - - -

I took it to Advanced Auto and also got a fail:

• No Load Voltage: 12.55 V

• Loaded Voltage: 12.58 V

• Ripple Voltage: 31 mV



I’ve got some questions:

1. Are these testing methods reliable? They were hooked up to battery only. I haven’t done a direct multimeter test on the alternator yet.

2. The alternator was tested by NAPA in April 2021, so it may have been sitting in a box since then. Could that affect its performance?

3. I tried installing a new serpentine belt but couldn’t get it on, so I put the old one back. The old belt looks shiny but isn’t cracked or loose. Could this impact charging?

4. There’s a sound coming from under the hood, like a fast-paced “card in bike spokes” noise at idle. I’m unsure if this is new or if I just hadn’t noticed it before. I was listening for pulleys or tensioner but sounded more like engine side??

5. Battery terminals look good, and I’ve bought new fuses, but I’m unsure which ones to check.


Any guidance on what to troubleshoot next would be greatly appreciated! Is it possible I got a faulty alternator, or could something else be causing the low charge?

 

Listening to a radio for an hour should not be enough to kill a good battery.

The alternator is not supplying voltage according to the test. Why would you buy one place and test at another?
Suggest you take it back and tell them it was DOA.

Next, terminals look ok is a sign. Suggest you take that abused battery with you when you exchange your alternator and have it load tested.

Armed with a new alternator and tested battery go forth and be successful.

Alternator output about 14.5V
Battery fully charged and at rest 2 hrs with open circuit about 12.7V for a basic FLA. SLA and AGM higher.

 

Has anyone load tested the battery?