2007 Toyota Yaris - 6 months of a warning light

Hi everyone. So I had a battery light on for about 6 months, on and off, with no starting or driving issues. Then the battery light started staying on, and not long after that I began having rough start issues. I had the alt->battery voltage tested, and it was fluctuating, so I thought my belt might be skipping and not sending consistent charge to the battery. Went home, took off belt and felt all pulleys by hand ( on my car its just alt, water pump which acts as the tensioner, ac comp and crank). All felt fine. Had the alt bench tested and it was junk, so I replaced alt and battery. Batt light stayed on :expressionless:, albeit it was dim. Week or two in hard starting came back and a cam position sensor code popped up. That now goes on and off, but I have a horrible noise under the hood. Could I have ruined the bearings on a pulley, or worse? Maybe pushed an old part over the edge by overtightening the belt? I’m going to start by removing the belt and feeling all the pulleys again (maybe autozone sold me a crap alternator) but if they feel good I’m not sure what to check next. The noise is a mix of grinding/knocking. It did NOT make this noise before alt replacement. Any suggestions?? Thx in advance, Maya

It certainly sounds like a second look at the belt/alternator repair is worth the effort. Take the alternator back for a full test.
Review online to find a video to show you what a properly adjusted belt would show for “play”.


I’m with @oldnotdeadyet. I suspect a bad alternator New parts can be bad out of the box.


It was a bad alternator lol. Simple, annoying, cost free fix. Ty


Good to hear. Happy motoring.

Cost free but you still provided the labor!

Just so you know… There are 2 or 3 levels of parts sold in these types of stores.

  1. The “I’m selling this car in 2 weeks” parts - you bought that one

  2. The “I just gotta keep this thing running another year” parts

  3. the parts the mechanic’s buy and install because they know 1) and 2) parts are junk and they don’t want replace the part for free with their labor.

If the alternator fails 6 months from now, try to get the good parts. You’ll pay more, but you’ll get more.