For the past couple weeks, I've intermittently seen my battery light and brake light illuminated at start. If it occurs, it usually goes away after I start driving. After a quick test with my multi-meter, I see 12.3 V off and 11.4 V during ignition. I did see the lights during this particular startup, which I think makes sense since it doesn't appear that my alternator was charging the system. What's odd, is as soon as I step on the gas a little, I see the voltage rise to 13.5 V. I'm not sure if it got to 14 V or not. After that I can idle and see the battery charge fine. Do you think this is just the alternator starting to go?

I should note that the car drives fine nor do not see any dimming in the dash or anything like that.

Thanks again,
--Matt

 

Disconnect the battery.

Disconnect the battery wire from the alternator, wire brush, apply electrical anti-oxidation grease, bolt it back on. Clean up the connections on the battery as well, same with the ground wire where it bolts to the chassis right next to the battery, same with the engine bonding jumper from the timing chain cover to directly below the coolant reservoir. Leave the coolant reservoir hose attached, just take out the single 10mm bolt and lift it straight up to access that jumper wire below it.

If the problem still persists after you've thoroughly cleaned up the connections then you probably have a slightly failing alternator, it should be pushing 14.5 volts out while the engine is running when everything is clean.

 

I'll give it a shot. Thanks!

 

UPDATE: When I got under the car to replace the alternator I found that it was covered in gunk. I thought it could be really old oil from an oil leak at first but ultimately it turned out that my power stearing pump was leaking. It looks like the leak had gone and damaged the alternator. I had the pump, high pressure hose, and alternator replaced. I enjoy being a weekend warrior but once I realized the job was larger that I had prepared for, I had to get some help. It's my daily driver and I needed it. Anyway, the problem is fixed. Currently 213K miles and going strong. I'm sure I'll be back with another mystery before long.