JLM09LTZ
Full Member
Not sure if this as been covered completely or not but here's the deal, my 09 Avalanche LTZ 5.3 Flex Fuel has been having weird intermittent electrical issues for about a month now. It all started when I noticed it would hesitate whenever I went to turn the key and start it up. Almost the same click sound synonymous with a failing starter. Later that day, the truck went into total flip-out mode. The door locks were jumping up and down, the dash lights went nuts, the truck would come out of drive and back in without shifting the gear lever, seat belt chime was singing and so on. I scooted the truck back up my driveway and as soon as I turned the key off, everything died. Popped the hood, wiggled the battery cables and it came back to life. I put a quarter turn on the battery terminal nuts and the truck seemed to be fine after that. I drove it 80 miles that night, no problem. Fast forward a week or so, as I was driving, I noticed whenever I hit the brakes, the headlights flickered. Then I started noticing that the voltage gauge was dropping severely at idle with the brakes applied, I'm talking below 12v. So naturally, I'm thinking the alternator was going bad and maybe that's been the issue the whole time. I replaced my original 145amp with a brand new Delco 160amp and replace that braided ground strap next to the master cylinder with a new cable. Test drove it that evening and everything seemed ok. Fast forward to last week, we got a pretty good heat wave here in the Cleveland area and I had the A/C kicking. I would notice again that the voltage would drop dramatically at red light with the A/C on, but whenever I turned the A/C off, it would be in the normal fluctuating range (within spec of the economy mode voltage drop). This past weekend, I had to drive it to Cincinnati and again it was hot. It was fine for about 2 hours in but then I began to notice that every time I hit the brakes or turned on my turn signal to change lanes, the radio would cut out. This time, it was happening while moving 75-80mph. Driving in Cincinnati and on the route back home, I decided not to risk it and I ran without the A/C on at all. Everything was good. Fast forward to Today, I'm in line at Wendy's, no a/c, no phone charger plugged in, nothing and the voltage dropped so low that the radio cut out and the dash lights and seat belt chime activated as if someone just turned it on. I'm beginning to think I may have a bad computer or something. I'm trying to figure this out before shelling out a ton of money to a shop. Has anyone had this issue?? Does anyone have any ideas?? I will literally try anything at this point.
Just some info on the truck:
-2009 Avalanche LTZ 5.3 flex fuel
-184,000 ish miles
-Every major component is original minus the belt, battery and alternator, and a few miscellaneous parts like the drivers side engine mount, front end components etc..
- The truck gets oil and filter changes religiously every 4000 miles and I only use Delco oil
- Most importantly, it has no added on aftermarket electrical accessories what so ever
- It does however have pretty much every electrical feature GM offered like the Bose system with rear screen and navigation and the power running boards, auto wipers, heated and cooled seats, etc
-No tow package though
Pleeeeez!! Any help would be greatly appreciated!
Just some info on the truck:
-2009 Avalanche LTZ 5.3 flex fuel
-184,000 ish miles
-Every major component is original minus the belt, battery and alternator, and a few miscellaneous parts like the drivers side engine mount, front end components etc..
- The truck gets oil and filter changes religiously every 4000 miles and I only use Delco oil
- Most importantly, it has no added on aftermarket electrical accessories what so ever
- It does however have pretty much every electrical feature GM offered like the Bose system with rear screen and navigation and the power running boards, auto wipers, heated and cooled seats, etc
-No tow package though
Pleeeeez!! Any help would be greatly appreciated!