Starting/ electical/ alternator + really cold weather

[AnsonJ]

Ok here is the back story... Monday it was -6 degrees out. I poked my head out the door and hit the remote start so the car would be warm when my son was ready to go out the door for school. Started up, engine turned a little bit slower, but it ran. had a really bad accessory bearing noise on start up. watched it run for a minute or so, bearing noise improved a little. I figure I would be looking at a water pump/ idler/ alternator in my near future. Son takes about 20 min to get ready, by that time the car had shut off. not sure when in the process that it shut off, but usually it runs for 10 minutes and if you dont stab it with your keys it turns off, so no biggie. car was somewhat warm (-6 degrees outside) put the key in and turn it. *Nothing*. no odometer panel, no clicks no noise just nothing. Dome lights were on.

figure alternator may have took a dump. anyways, yanked the battery out so it wouldn't freeze if it was discharged, put it on the trickle charger, went to full charge fairly quickly, within a few minutes. battery did have some white crusties on the negative terminal but very flakey/ fluffy and brushed off easily. Took the battery to Autozone, it tested good. battery is 5 years old. when I took the battery in I asked if the alternator could be tested out of the car, and because it is the 3.9 L the Autozone guy said that the PCM does a lot of the functions for the regulator for the alternator and needs to be tested in the car. ok so I decided to see what a used alternator would cost. here in the Indianapolis area an alternator for a Buick Lucerne 3.9 liter engine is pure unobtainium. anywhere from 200 to 400 bucks new/ reman from the autoparts store. Looks like I might be able to get one 2 and a half hours away... but other than that... Another thing I noticed, I removed the alternator and it spins freely with no noise or bearing issues. However the idler pully right next to it feels rough, so I imagine that is what I heard. gonna replace that.

So my question to you guys is would a dead alternator cause the pcm to not allow the car to start?

Anson

Edit: 2010 Buick Lucerne CX with 3.9L flex fuel engine, 150k miles

 

[2007LucerneCXL]

A 5 year old battery and 150K alternator could both be at the end of life cycle. Getting the entire charging system checked may eliminate guessing but the alternator can be tested outside the vehicle. Not mentioned if the battery was load tested or how many months the battery is rated for, if it's a 48 month and it's going on 60 months time to replace.

On the remote start if the HVAC, radio and lights were on and the battery or alternator was in question there is a possibility that it didn't get much if any charging during 10 minutes of idling especially on a frozen battery.

07 CXL in Illinois so I can relate to the weather conditions lol.

 

[century61]

I am in Northern Indiana. No problems starting my car but I do not have remote start. My S.O. does though.
I do not think your alternator is bad. You would have had a warning light on your dash for battery if it was. Also, The charging system I do believe works with the PCM to monitor the battery and the draw on it. If there is not any real draw on the battery then it does not charge it. When the draw rises then it begins to charge the battery. I havent had any issues with my charging system so Im not sure if the 07 is before that feature was implemented.

I think when you disconnected the battery for testing it reset everything in the car and cleared a condition for the remote start and enabled the starting of the car. I wouldnt worry about that. I think my S.O. 's Lucerne does the same thing. Also, If there is any warning light on - on the dash the remote start will not work.

Now for the noise. Grab a BIG screw driver and a one gallon jug like they sell with wiper fluid. Cut the bottom of the jug off. Take the screw driver and run it thru the top of the jug so the handle is inside the jug. Start the car and carefully hold the screw driver tip to the pully's and alternator - one at a time. The jug acts like a amplifier and speaker so you can hear the sound better and isolate it. I bet its the tension pulley making the noise.