Pretty sure my alternator just went out. Need Advice

[JJ93]

Hi everyone! I'm pretty sure my alternator just went out, but I want to see what you guys think.

I left this morning to head to the upper peninsula for a few days. The truck was running fantastic. About 25 miles after crossing the mackinac bridge my battery light came on, and my volts were showing about 12. I pulled off the road and restarted the truck, and after a minute the volts went back to 14. I drove another 10 minutes and then the light came on again for the battery, and my volts were dropping. Seeing as how I had no phone signal in the middle of the wilderness, I decided to turn off all electronics and press on for another 25 miles until I hit the next town (only to find out all the parts stores within a 1 hour drive were closed today). The truck made it but was obviously getting low on charge. So here I sit in a hotel room until tomorrow morning when the parts stores open up.

Do my symptoms sound like a failing alternator to you guys? I'm assuming my '01 Suburban has the 130 amp alternator?

Thanks in advance everyone!

 

[Scottydoggs]

id check that the battery cables are tight. you can also take the belt off and hand spin the alt pulley. if its really hard to turn, or you can hear it or feel it grinding. its bad.

also get the battery load tested before you buy a alternator. with the battery tester tool at the parts store, most have one for free use. you can test the load the battery is good for, and see volts of the battery engine off, and running, off you want to see 12, but that might be low due to the bad alt. running you want to see 13-14 volts. if you dont get that 13-14 running the alt is failed for sure.

only good thing here is the battery or the alt is a quick swap in the parking lot with minimal tools.

 

[JJ93]

id check that the battery cables are tight. you can also take the belt off and hand spin the alt pulley. if its really hard to turn, or you can hear it or feel it grinding. its bad.

also get the battery load tested before you buy a alternator. with the battery tester tool at the parts store, most have one for free use. you can test the load the battery is good for, and see volts of the battery engine off, and running, off you want to see 12, but that might be low due to the bad alt. running you want to see 13-14 volts. if you dont get that 13-14 running the alt is failed for sure.

only good thing here is the battery or the alt is a quick swap in the parking lot with minimal tools.

Thanks man. I will check those things for sure. I haven't verified the voltage with a voltmeter but I did check with the torque app on my phone and after running for a bit without the alternator it was starting to drop below 12 volts. The more I think about it the more it is sounding like the alternator. I did hear a very minor grinding coming from what sounds like the alternator area that was getting worse.

I guess that verifies it then haha.

Thanks for your advice!

 

[OneofFew]

Mine did the same way when the regulator went bad in the alternator.

 

[HiHoeSilver]

Hi everyone! I'm pretty sure my alternator just went out, but I want to see what you guys think.

I left this morning to head to the upper peninsula for a few days. The truck was running fantastic. About 25 miles after crossing the mackinac bridge my battery light came on, and my volts were showing about 12. I pulled off the road and restarted the truck, and after a minute the volts went back to 14. I drove another 10 minutes and then the light came on again for the battery, and my volts were dropping. Seeing as how I had no phone signal in the middle of the wilderness, I decided to turn off all electronics and press on for another 25 miles until I hit the next town (only to find out all the parts stores within a 1 hour drive were closed today). The truck made it but was obviously getting low on charge. So here I sit in a hotel room until tomorrow morning when the parts stores open up.

Do my symptoms sound like a failing alternator to you guys? I'm assuming my '01 Suburban has the 130 amp alternator?

Thanks in advance everyone!

Your alternator will be specified by the K code on your RPO sticker in the glove box.

 

[JJ93]

Your alternator will be specified by the K code on your RPO sticker in the glove box.

Thanks for that!

 

[ivin74]

Check the fuseable link that goes from the alt to the battery, I had that burn out on my silverado and had similar symptoms.

 

[Rocket Man]

Update us on what you find out this morning.

 

[JJ93]

Sorry guys, I've been driving all day. The alternator did test bad, it wasn't putting out anything at all. I installed a brand new one in the parking lot at the auto parts store (in the snow lol) and it has been running great!!

Thanks everyone for the suggestions!

Edit: I'm surprised how far I could drive on just the battery lol. From the time my alternator went out until I finally was able to replace it i drove about 38 miles. I never want to do that again haha

 

[Rocket Man]

Sorry guys, I've been driving all day. The alternator did test bad, it wasn't putting out anything at all. I installed a brand new one in the parking lot at the auto parts store (in the snow lol) and it has been running great!!

Thanks everyone for the suggestions!

Edit: I'm surprised how far I could drive on just the battery lol. From the time my alternator went out until I finally was able to replace it i drove about 38 miles. I never want to do that again haha

Thanks for following up. Glad you got it fixed and back on the road.

 

[OR VietVet]

IMO, unless the battery is fairly new, less than a year old, I would change the battery too.

 

[HiHoeSilver]

Sorry guys, I've been driving all day. The alternator did test bad, it wasn't putting out anything at all. I installed a brand new one in the parking lot at the auto parts store (in the snow lol) and it has been running great!!

Thanks everyone for the suggestions!

Edit: I'm surprised how far I could drive on just the battery lol. From the time my alternator went out until I finally was able to replace it i drove about 38 miles. I never want to do that again haha

What size alternator did it turn out to be?

 

[JJ93]

I believe the battery is a year or so old, I'll double check. It fires right up without hesitation though, but I'll keep an eye on things. The alt did turn out to be a 130 amp like I hoped. I put almost 600 miles on it so far and it has been consistently putting out great voltage, even with every accessory on.

I wish I could've put in a new AC Delco unit but I wasn't about to pay what the GM dealer wanted. I got a Napa premium which had good ratings and a good warranty. If it doesn't work out, I'll order a new Delco unit online.

I think within the next few weeks I'm going to replace the thermostat, water pump, and hoses just for good measure. I'm not having problems with them, but I hate when things go wrong on the road that could've been avoided.

Also. This is the best road trip vehicle I've ever owned. So comfortable and sure footed no matter what the weather is. And I got 18 mpg to boot!

 

[OR VietVet]

"I think within the next few weeks I'm going to replace the thermostat, water pump, and hoses just for good measure. I'm not having problems with them, but I hate when things go wrong on the road that could've been avoided."

My dad taught me a long time ago that "Maintenance pays and breakdowns cost".

 

[JJ93]

Totally agree. It's worth the peace of mind for sure. I've even tossed around the idea of replacing the fuel pump next spring just so I don't have to wait for it to go out. I know if I wait for it to go out, I'll be dropping a tank that has 30 gallons of gas in it lol. It just seems to be my luck!

 

[OR VietVet]

When I bought my 2002 about 3 years ago I got all the maintenance and repairs paperwork with it and all work had been done at the Chevy dealer about 1 block from me. The fuel pump was replaced at about 125k miles and is now at 159k.

Keeping the fuel clean and replacing the fuel filter when you should helps the pump work easier. Pisses off the pump to try and push fuel thru a clogged filter. Also, try to think of 1/4 tank of fuel as empty. The pump likes being submerged in the cooling effect of the fuel all around it.

Fuel pumps never shoot craps in your driveway either.

The maintenance and certain parts replacement can be planned on and you know how much it will cost ahead of time where a breakdown always costs more.

 

[Mercerbeef]

My alternator just went , had to charge the battery as it ran down. Replaced the alternator and when we tried starting it , everything lights up and flash’s And clicks but no start.
Could it be an alarm system? There’s no sounds of horns but it flash’s the lights inside and out like an alarm system . If it is how would I find out how to disarm it?

 

[wjburken]

My alternator just went , had to charge the battery as it ran down. Replaced the alternator and when we tried starting it , everything lights up and flash’s And clicks but no start.
Could it be an alarm system? There’s no sounds of horns but it flash’s the lights inside and out like an alarm system . If it is how would I find out how to disarm it?

Are you using jumper cables or did you charge the battery with a charger?

Make sure you have a good ground on both vehicles.

 

[OR VietVet]

If cables let it just sit there for a minute or two and charge from the other vehicle while idle is higher or longer on the charger. How long did you charge the battery? If you just hooked up and tried to start right away the battery needs more help. Runs the battery down quite a bit without an alternator. If battery is old enough it may not come back to life so easy or quick.

 

[Mercerbeef]

It died about 2min from my house and my brother in law pulled me home. Had to remove the battery to charge it. Battery is fully charged.