Charging system indicator light when accelerating

[AmandaOK]

2007 Rendezvous
Charging system indicator light when accelerating like when getting on the interstate or getting up to speed on the hwy. If I keep accelerating more lights come on air bag, brake, anti lock, ect. If I stop accelerating the lights shut off.

Replaced plugs and wires (shortly before the problem started), serp belt and tested battery and alternator

Dealer diagnosed a C0 896 code and cleared it calling it a "computer glitch" and they test drove it 3 times (probably in the lot) and couldn’t get the light to come on... I pick it up and drive a block to the interstate and get on and my light comes on...

But the dealer also didnt listen to me when I said it is the "Charging system indicator light" and all that a$$ hole heard was "ABS and ESC"(which was not what I said) so I honestly dont trust their judgement.

I am not sure if this is a symptom or not but it has been starting hard. Or it will start and kill right away. Then I restart it and acts fine... I say I am not sure this is a symptom because I have noticed (and owned) other GM vehicles that start like this.

We can not afford to take it back to the dealer at $50 an hour. My husband is mechanically inclined and works at O'Reilly Auto Parts so he gets good prices and he does all repairs himself.
BUT we are at a loss as to what is causing this.


HELP!!😱
Any suggestions would be appreciated!

 

[Buick Customer Service]

I would be happy to assist you. Please contact me privately with more information, including the last eight of your VIN, for more assistance. Thank you in advance.

Tricia, Buick Customer Service.

 

[AmandaOK]

New symptoms:

Cruise shutting its self off
Radio Static
Radio Static when cell phone plugged in to cig lighter to charge.

 

[AmandaOK]

 

[sho-man1]

Ours started doing the same thing after the dealer performed the 100K service. I have had the battery and alternator checked at O'rielly s, both checked good. Dealer then said to replace alternator for $500, I said not today. I will stick an analog volt meter on it this week while I drive to watch voltage.

 

[AmandaOK]

Let me know what you find out! I'm sorry to hear that it's happening to you too. My husband lost his job 2 weeks ago so sadly we have put off having ours diagnosed until he has a job again. Thankfully it still drives even though something's wrong or we would be in trouble.

My husband checked out alternator on and off the rendezvous and both times it checked out okay. And it's not cheap to just replace to eliminate that as the problem. I honestly think its the computer. Someone also suggested the ABS Hydrolic Module.

 

[midnightmekanik]

I've had a similar problem, but on another car (a 91 Z24). I repeatedly tested the alt and battery, both were good. I finally broke down and replaced the alt, but it still had the problem. I then checked the wiring harness going to the alt, and checked each wire with a multimeter at both ends. I found that a wire was broken in the loom. It was a green wire, which was a charge sense wire. As the car accelerated, it drew more power from electrical, but without the sensor wire being intact, the alt kept charging as if it were at idle. All kinds of lights would go on, ligths would dim, etc.

May not be the cause, but something to look at.

 

[sho-man1]

The Buick took a road trip and I had a volt meter in the cigarette lighter.
It started displaying the "charge/battery" symbol and the volt meter would jump to 15volts, then 16 volts then settle back to 14. When the meter was hitting 16 volts all the dash warning lights would illuminate...Me thinks a diode is giving up the ghost and the output of the alternator is going more AC. Wish I had an O-scope while this was going on. It is hanging over 100 degrees, I think my neighborhood mechanic is going to take care of this one this time.
Like before, the charge/battery light comes on under heavy acceleration like getting on the interstate or lugging the engine at 2200rpms at 65-70mph. I either back off the accelerator or hit it so the transmission drops a gear.
I'll let you know what my trusted mechanic finds.

 

[AmandaOK]

midnightmekanik- we checked out the wire you are referring too... it looks as though it has been exposed to heat. We replaced the wires with wire we had in the garage and the lights still come on... we will not cross this off the list until we put in brand new wire in.

Here are some pictures for people to check their's for heat exposure.

VVV--- This is the wire. It was tucked down under and my husband pulled it up to keep from the heat it was being exposed to.

VVV--- Heat damage

VVV--- Alternator wires they are a red and a light green you can see the heat damage(sort of) blury picture sorry

VVV---another picutre of the heat damage on the wires by my finger tips(near the tape)

VVV--- the wire group

 

[AmandaOK]

sho-man1 Check your wires for heat damage like mine had. It didnt fix our problem but that could be because we put bad wire back in... or didnt replace enough of the wire.

 

[AmandaOK]

sho-man1... Our problem sounds exactly the same. I will be very interested to see what your trusted mechanic says... wish we had one of those "trusted" mechanics! Good luck!

 

[sho-man1]

I'll check the wires again this time looking for any heat/melt damage.
Thanks for the heads up.

 

[sho-man1]

I took the Rednezvous to the mechanic. He said it looks like one of the diodes in the alternator is going bad. Under the tests it all showed ok. He said that replacement would be the safe thing to do.
So I replaced it with a refurbished one from O'reilly for $179.
It took about five hours to swap.
1 park it and leave in neutral, set brake and chock tires.
2 remove battery, includes the cross mount bar.
3 lift the fuse box above the washer fluid tank out of the way.
4 unplug the wiper motor power, washer pump power and water hoses
for front and back.
5 remove the three 10mm bolts that hold the washer fluid tank.
6 use a 3/8 ratchet on the serpetine belt tentioner to loosen belt.
7 remove the belt tentioner and the idler pulley .
8 remove the three bolts holding the alternator, two in the back and one
on the side and unplug wire and unbolt cable.
9 remove the tentioner bracket, two bolts on the side and on bolt on the
top.
10 remove the two bolts on the front motor mount brackets so you
can roll the engine forward. You may have to slide out the black braket
that mounts between the tentioner bracket and engine block.
11 with help start manipulting the alternator out by rolling the engine
forward and not hitting anything.
Install new alternator just the reverse. There were a few zip-ties and wireloom clips that need to be released when moving stuff around.
My digital volt meter was showing 15.3volts on the old alternator, the new one was at 14.7volts.
Test drive of about 50 miles at highway speeds and rush hour traffic showed no more battery light or dash board light isses.
I wear safety glasses and mechanics gloves.

 

[AmandaOK]

Amazing!! Wish the alternator would test out bad so that our dealer would replace it under our warranty! Guess we will drive it until it goes all the way or until we can afford an alternator. Thanks so so much for sharing this with me(and everyone). It really broke my heart that a vehicle that I had only owned for 4 months could possibly have a major electrical problem. I have a little more peace of mind knowing its probably just the alternator.

I can't say thanks enough!

 

[sho-man1]

My wife bought her Rendezvous new in 2007 and it has been good...
I would still like to look at the output voltage of the alternator on an oscilloscope and see how much ripple is on it. I think that is what is going on.
Good luck.

 

[midnightmekanik]

Amazing!! Wish the alternator would test out bad so that our dealer would replace it under our warranty! Guess we will drive it until it goes all the way or until we can afford an alternator. Thanks so so much for sharing this with me(and everyone). It really broke my heart that a vehicle that I had only owned for 4 months could possibly have a major electrical problem. I have a little more peace of mind knowing its probably just the alternator.

I can't say thanks enough!

I wouldn't drive it too long like that. DC voltage computers don't particularly like AC voltage. Could end up costing way more than just buying the alternator. It's pretty easy to install, I actually put a larger one in my rendezvous. It was a tight squeeze, but it did fit with some twisting and turning. One tip, use a ratcheting strap with hooks. Hook one end to the engine hoist eyelet, traveling the strap in front of the rad support and the other end down below on the subframe. Crank the strap until the motor touches the plastic fan shroud. Nothing will break, I promise! LOL If you don't take it that far, it will be hell to get it out. It literally took me about 1 hour to remove/re-install while having a beer break after removal lol My problem was completely different though. I had a $1.00 plastic battery hold down clip that broke and allowed the battery to slide far enough that the positive battery cable did a little dance with the bolt heads on the water pump pulley. Not a pretty site when you saw the aftermath... Looked like a wolverine was trying to eat through the cable!!

 

[AmandaOK]

I wouldn't drive it too long like that. DC voltage computers don't particularly like AC voltage. Could end up costing way more than just buying the alternator. It's pretty easy to install, I actually put a larger one in my rendezvous. It was a tight squeeze, but it did fit with some twisting and turning. One tip, use a ratcheting strap with hooks. Hook one end to the engine hoist eyelet, traveling the strap in front of the rad support and the other end down below on the subframe. Crank the strap until the motor touches the plastic fan shroud. Nothing will break, I promise! LOL If you don't take it that far, it will be hell to get it out. It literally took me about 1 hour to remove/re-install while having a beer break after removal lol My problem was completely different though. I had a $1.00 plastic battery hold down clip that broke and allowed the battery to slide far enough that the positive battery cable did a little dance with the bolt heads on the water pump pulley. Not a pretty site when you saw the aftermath... Looked like a wolverine was trying to eat through the cable!!

Thank you we are looking into prices now and thanks for the tip! 🙂

 

[AmandaOK]

Today is the day!! My wiper motor went out Wednesday so we decided if we are taking that out we better change the alternator since the wiper motor and arms will be less to fight to get the alternator out. Found AMAZING price at LKQ $90 for remanned wiper motor AND remanned alternator!!! Can't beat that!! please keep your fingers crossed that the lights issue is the Alternator or we are in trouble!!

 

[AmandaOK]

The alternator did it!!! Damned thing! would have saved a lot of heart ache if the thing would have tested out bad!

 

[sho-man1]

Saga started again. The dash lights started flashing again. I pulled into o'riellys and had them check the battery and alternator...both are bad.
They are both under warranty and O'riellys gave me new ones. Still took four hours to swap the alternator.