Have to change my battery...dont wanna f*** my car up. HELP needed quick

CReynoldsMIZ

Original poster
Member
Oct 29, 2012
30
Ok guys, tried searching around. Limited sketchy info. Here's my problem, knew my battery was going to need replaced soon, went out to go to Taco Hell, nope, the cold has taken the Envoy with it. Havent lost complete power, but pretty much. So what is my best (CHEAPEST) safe method to change the battery. Here's what ive learned...

Changing Battery w/o back can cause
1) Rough Idle, stalling
2) Throws codes
3) HVAC actuators failures

How to prevent it
1) Portable "Backup Battery" computer memory saver
2) The cord memory saver plugged into the OBDII
3) Pray to God almighty with neither and hope everything works

So obviously the battery backup thing is the best option, but to tell you the truth im a broke college kid 1 week from graduation and cant afford it. Does the extension cord thing plug into the cigarette lighter (of another car i presume????) do the same thing, just cheaper? How effective is it? Will it prevent the HVAC motors from messing up? I havent cleaned my throttle body (on my list) probably ever and dont want to this week, so im trying to take all precautions to save my car and its stuff.

Is it possible to hook up jumper cables from a good car battery to my car from the using the 12V post under the engine fuse box and the ground going to the engine block? Would that do the same thing and save all of my settings? Or is it a risk to something? If that could be done it would be awesome because i already have cables and no other expenses will be lost. Whats the chance of messing something up by not doing any of these measures?

I learned all this from May03LT's youtube page (searching google how to remove memory box lol, but no I can turn a wrench just have never replaced this battery before) I gotta do this tomorrow so any help would be awesome. THANKS!
 

Sparky

Member
Dec 4, 2011
12,927
I haven't had to replace my battery yet but I do disconnect it every time I clean the throttle body. Nothing bad has happened yet.

If it were me, I'd pull the old battery, then clean the throttle body, then put in the new battery. That will make sure there isn't any gummy throttle body induced rough idle or stalling.
 

Voymom

Member
Feb 3, 2012
2,523
I have also disconnected my battery a few dozen times in the 11 months I have owned my Envoy, and I have never had an issue.

If you are expecting issues when you change out the failing battery, you should expect the same issues if it does die on you...and then it really wouldn't matter what you may face, because it will happen anyways..just my two cents.

I would however, make sure all your electronics were turned off, including the HVAC system when you go to disconnect the terminals. :thumbsup: good luck!

Edited to add- The ONLY issue I had when reconnecting the terminals on my battery, or when jumping my dead battery was the head light washers soaking me. Other than that, nothing bad ever happened.
 

RayVoy

Member
Nov 20, 2011
939
Voymom said:
Edited to add- The ONLY issue I had when reconnecting the terminals on my battery, or when jumping my dead battery was the head light washers soaking me.
That's the "wet t-shirt contest" feature, RPO code WTC :raspberry:
 

MAY03LT

Member
Nov 18, 2011
3,420
Delmarva
CReynoldsMIZ said:
So obviously the battery backup thing is the best option, but to tell you the truth im a broke college kid 1 week from graduation and cant afford it. Does the extension cord thing plug into the cigarette lighter (of another car i presume????) do the same thing, just cheaper? How effective is it? Will it prevent the HVAC motors from messing up? I havent cleaned my throttle body (on my list) probably ever and dont want to this week, so im trying to take all precautions to save my car and its stuff.

Are you talking about the double ended cord thing that I showed with the OTC memory saver? That was only 2 ft long so it couldn't go to another cars cig lighter. If there is a super long one, it would work the same.

CReynoldsMIZ said:
Is it possible to hook up jumper cables from a good car battery to my car from the using the 12V post under the engine fuse box and the ground going to the engine block? Would that do the same thing and save all of my settings? Or is it a risk to something? If that could be done it would be awesome because i already have cables and no other expenses will be lost. Whats the chance of messing something up by not doing any of these measures?

That would work too. There's a vid on youtube where someone did something similar to keep the memory alive during a battery service. I would be super careful working around where positive jumper cable is connected, you don't want that thing to pop off and touch metal.

Also, good job researching this stuff first:thumbsup:
 

Voymom

Member
Feb 3, 2012
2,523
RayVoy said:
That's the "wet t-shirt contest" feature, RPO code WTC :raspberry:

:biggrin:
 

c good

Member
Dec 8, 2011
532
I just connected some jumper cables from a second vehicle to the red post on the fuse block for positive, then the fender body ground for negative. This info came to me from the Guru of GMT Nation. Remember...you're not "jumping" to start the engine with this set up. You're just keeping power to the system. Mine worked like a charm. No lost codes, no blown up HVAC actuators, no re-programming my sound system. HTH c good
 

CReynoldsMIZ

Original poster
Member
Oct 29, 2012
30
MAY03LT said:
Are you talking about the double ended cord thing that I showed with the OTC memory saver? That was only 2 ft long so it couldn't go to another cars cig lighter. If there is a super long one, it would work the same.

That would work too. There's a vid on youtube where someone did something similar to keep the memory alive during a battery service. I would be super careful working around where positive jumper cable is connected, you don't want that thing to pop off and touch metal.

Also, good job researching this stuff first:thumbsup:

They sell these type of things at my local parts place (o reilly's, advance auto). Not exactly sure how it works, or if it is really only good for the engine stuff and not the actuators? Here's a link...E-Z Red MSBD28 Auto Memory Saver : Amazon.com : Automotive

Any idea on a link for that video? Can you explain this concept to me, it was an just an idea. So if i plug the +12v onto the other car battery, ground the negative to that battery and one to my engine block ground, that would keep power to all of my stuff, is that correct? I really dont know anything about this wiring setup, or if that would even work.

Yup, all come out of necessity. I went out to grab some grub, was 15 degress last night and cold today. Went to start it, wouldnt start. Popped the hood, tried to remove the cover, wouldnt come off. Wondered for a sec if I have to take that black brace off, then thought, oh, ill just look at youtube, im sure May03LT has something on that. Surely you did, then i figured out all these other "little" problems that could happen w/ a 10 year old car with 120,000. I promise, ill get that throttle cleaned, just absolutely dont want to do it during finals week and graduation!!!
 

CReynoldsMIZ

Original poster
Member
Oct 29, 2012
30
i've also read you can swap the battery out with the car running? Is that possible/ recommended??
 

CaptainXL

Member
Dec 4, 2011
2,445
CReynoldsMIZ said:
i've also read you can swap the battery out with the car running? Is that possible/ recommended??

Unless your jumped to another battery i would not recommend it. You could blow out the voltage regulator in the alternator. But even that would be tricky to do unless you had a firm grip on the terminals which are covered by the insulator boots.

C good seems to have the answer.
 

CReynoldsMIZ

Original poster
Member
Oct 29, 2012
30
okay. so just to be clear, the method of jumper cables connected to a car with a good battery (car shut off of course), connected to my 12v jumper post under the fuse box and the ground to the engine block (by the alternator i think?). That should keep all my memory, right?
 

Sparky

Member
Dec 4, 2011
12,927
Yeah should work. Just be careful when swapping your battery as that positive terminal will now still be live when you disconnect it from the battery, so don't let it fall against anything metallic or touch your wrench to the chassis when loosening/tightening its bolt!
 

CaptainXL

Member
Dec 4, 2011
2,445
If your battery has ever died on you or ran below 10 volts at any time in the vehicles life then what your doing here is kind of futile. I would just disconnect the old one and wait 1 hour then hook up the new battery. If there is something on the truck that's gonna fail You are gonna want to know about it now rather than coming back to bite you while your driving.
 

CReynoldsMIZ

Original poster
Member
Oct 29, 2012
30
CaptainXL said:
If your battery has ever died on you or ran below 10 volts at any time in the vehicles life then what your doing here is kind of futile. I would just disconnect the old one and wait 1 hour then hook up the new battery. If there is something on the truck that's gonna fail You are gonna want to know about it now rather than coming back to bite you while your driving.

How is that? As long as i have had some power at all times, even if it was low. all my settings should still be correct
 

CaptainXL

Member
Dec 4, 2011
2,445
CReynoldsMIZ said:
How is that? As long as i have had some power at all times, even if it was low. all my settings should still be correct

Maybe. I don't have the PCM or BCM electrical component diagrams and specs so knowing this with any deal of certainty is guessing at best.

Some logic such as the PCM always needs a certain voltage applied to it before it turns off. What this limit is I don't know but it can't be far below 12 volts.

I'm not saying you can't do the jump method. All I'm saying is that it's not any better of a method than just disconnecting the battery. I highly doubt you will have any problems. I must have disconnected my battery 100 times by now and nothing has ever just blown up.
 

ScarabEpic22

Member
Nov 20, 2011
728
Shut off car, open hood. Unbolt battery brace. Disconnect negative terminal. Disconnect positive terminal. Remove. Reverse for new battery.

I know people freak out about the HVAC stuff, I cant tell you how many times Ive pulled the battery in my 02 and SS. Never had an issue in the 7+ years Ive been working on them (7 for the 02, 3.5 for the SS).
 

Wooluf1952

Member
Nov 20, 2011
2,663
Milwaukee, Wisconsin
To the OP: Sorry if I missed it, but what year is your truck, do you have the I6 and how long since you last cleaned the throttle body?
Disconnecting the battery may not affect any thing, it could just cause the engine to run bad (if the t-body is really gummed-up) or it could affect the HVAC.
If you have no place warm to do the t-body or don't want to take the chance of having to change/repair the HVAC, just use the jumper cables and (as noted above) be very careful with the battery cables. Also, turn off everything before battery disconnect. :twocents:
 

CReynoldsMIZ

Original poster
Member
Oct 29, 2012
30
Wooluf1952 said:
To the OP: Sorry if I missed it, but what year is your truck, do you have the I6 and how long since you last cleaned the throttle body?
Disconnecting the battery may not affect any thing, it could just cause the engine to run bad (if the t-body is really gummed-up) or it could affect the HVAC.
If you have no place warm to do the t-body or don't want to take the chance of having to change/repair the HVAC, just use the jumper cables and (as noted above) be very careful with the battery cables. Also, turn off everything before battery disconnect. :twocents:

Sorry, it is an 02 GMC Envoy SLT. Yup its got the I6, 4wd, loaded yada yada yada. I bought the car Jan 2010 from my grandpa, original owner, with 80,000 on the odometer. Car has 120,000 on it now and most of the last 40k are from highway (home to school, 140 miles each way). I have ONLY done oil changes on it the last 3 years, nothing else. I got a whole list of maintainence to do on it including

-Throttle body
-air cleaner
-transfer case oil change
-differential oil change(s)
-rear coil conversion
-tires
-coolant change
-maybe tranny flush
-spark plugs
-serpentine belt

Ive have been a broke college kid for the better part of 4 years now, and with graduation on Saturday, im literally just trying to find a way for the car to keep running good the next month til i plan on doing all of this stuff in January back home where all my tools are. Car has no mods, just got 1 small Infinity sub in the rear (no crazy bass). The car has ran absolutely perfect the entire time I have had it, and all ive had to do to it was buy a 6$ ambient temp sensor and thats it, and my grandfather always keeps his cars running good, but I dont know what kind of maintence he has the dealer do for him, anything prior to 80k miles, I dont really know about. I wouldnt say that i have "neglected" the car, because i keep it mighty clean and really drive the car easy (I found cars seem to last WAY longer and not nearly as many problems if you just drive them easy), but yeah, I also understand that I got some stuff I need to do to it real soon.

Im gunna try the jumper cable method with my buddies toyota highlander, so here's hoping it all goes well! Are there any batteries I should absolutely stay away from???
 

Sparky

Member
Dec 4, 2011
12,927
Don't get an Optima. They aren't what they used to be and the price premium isn't worth it.
 

CReynoldsMIZ

Original poster
Member
Oct 29, 2012
30
Sparky said:
Don't get an Optima. They aren't what they used to be and the price premium isn't worth it.

Just going to get an ACDelco from the dealer, they actually have the best price around town i could find on batteries, about 10-20 lower than walmart. I was shocked when i heard them. The one I have in there now is an ACDelco, havent had any problem w/ it in 3 years, and not sure when it had been replaced before that. Never a problem with it except these last couple weeks
 

eutechnyx

Member
Mar 31, 2012
375
Ive disconnected my battery quite a few times for various reasons and NEVER knew about any issues. What issues does the 03 envoy have with disconnecting the battery? this has me wondering lol.
 

CReynoldsMIZ

Original poster
Member
Oct 29, 2012
30
OF COURSE! I go to the dealer to get a new battery with the help of my buddy, we go to put the new one in, and after hooked up the cables from his car to my car to save the memory (Which worked beautifully by the way), I hook up the positive battery in, and find out the positive battery bolt is stripped and the threads are F'd up. Buddy had to leave to go to work, so now I got my car sitting there with the positive bolt barely hanging in there just to keep the power connected, not enough for me to go out and drive. Now i gotta get another buddy to come drive me to the store, get a post, come back, hook up the cables again, and put a new post in. God, why is all the easy stuff always so difficult!
 

Sparky

Member
Dec 4, 2011
12,927
lol sounds like what I'd run into :crazy:
 

CaptainXL

Member
Dec 4, 2011
2,445
Those dual sided East Penn battery bolt wrenches you get at auto zone work awesome. Just got one the other day along with some East Penn bolts. The wrench gives you a better feel how tight they get. Keeps you from stripping the bolts. You just want to bottom them out snug or torque to spec.
 

c good

Member
Dec 8, 2011
532
On the other hand I had a driver's side actuator go bad after a battery disconnect. It's one of the "easier" ones to get to. Still was a couple of hours upside down on my back, jammed in under the dashboard, plus $85-$100 for the part IIRC. But hey..It's only time, money, and a sore neck and back right! Work smarter....Not harder.... An ounce of prevention is worth a pound of cure....all words of wisdom from generations past. c good
 

CReynoldsMIZ

Original poster
Member
Oct 29, 2012
30
c good said:
On the other hand I had a driver's side actuator go bad after a battery disconnect. It's one of the "easier" ones to get to. Still was a couple of hours upside down on my back, jammed in under the dashboard, plus $85-$100 for the part IIRC. But hey..It's only time, money, and a sore neck and back right! Work smarter....Not harder.... An ounce of prevention is worth a pound of cure....all words of wisdom from generations past. c good

Welp, went back to the dealer, got a new bolt for the positive battery. Hooked my buddies Duramax back up to my Envoy +Post under the fuse box to keep the power, I took two steps away to get a different socket, i look over an he's tightening the battery down and somehow touches the positive jumper cable hooked up to my car. Sparked for a second, i look, and the lights which had been on inside of the car are now off. Im thinking "i just went thru all of this work to keep the power going, now you come here and you mess it up". Now im thinking well just F it, we unhook those jumper cables, finish the wires on the battery, and pray to god and hope that short didnt do anything.........................................................................................................

Welp, lucky for me, it didnt! Car was probably only without power for a total of less than 10 seconds, the ol gal started right up, didnt loose my radio presets or nothin, just the clock. Took the car for a spin and ran great as usual, and the HVAC had no problems either! Maybe I got lucky, who knows, all i know is I learned a lot of info about this subject, and just glad its over and hopefully wont have the car the next time it needs a battery (one day ill buy myself a Rubicon or Duramax 2500!). Thanks for everyone's help!
 

Sparky

Member
Dec 4, 2011
12,927
Ha. Oh well no harm done :biggrin:
 

c good

Member
Dec 8, 2011
532
Another word of wisdom....don't let "friends" that don't know what they're doing work on your vehicle...:smile: Glad it worked out...thanks or the update. c good
 

MAY03LT

Member
Nov 18, 2011
3,420
Delmarva
CReynoldsMIZ said:
why is all the easy stuff always so difficult!

Welcome to the wonderful world of auto repair!:wootwoot:

So the jumpers worked ok? Coolness.:cool:
 

CReynoldsMIZ

Original poster
Member
Oct 29, 2012
30
c good said:
Another word of wisdom....don't let "friends" that don't know what they're doing work on your vehicle...:smile: Glad it worked out...thanks or the update. c good

Haha, actually he does know what he is doing. He has a tricked out Duramax and does most of the work on it himself, he's just kinda a putz and doesnt do things as thought out as i would lol

MAY03LT said:
Welcome to the wonderful world of auto repair!:wootwoot:

So the jumpers worked ok? Coolness.:cool:

Oh yeah, repair in general is that way. I actually spend more time working on or jet skis and atv's than my envoy, and have done engine rebuilding, replacement on them, so I like to work on my car every once in a while as well, (more so in my high school days), and you can be damned sure I aint gunna take my car to the dealer or shop to get something fixed, just dont trust others that well, and with you and your youtube vid's i should really be able to replace anything on it lol.

Well, in theory, yea the jumpers did work or "should've worked". I disconnected them after he somehow shorted the wrench to the jumper cable which shut off the power to the car, but before that the car did have power, so it is a good method, you just have to be really careful about swinging that ratchet because there isnt alot of room between the positive side post on the battery, and that top post on the fuse box.
 

CaptainXL

Member
Dec 4, 2011
2,445
eutechnyx said:
Is there a thread for ill effects of losing battery power,models effected etc?

Don't get all paranoid because of some people who have FUD on the brain.

Relax. There is nothing to worry about. Definitely nothing important to write about.
 

The_Roadie

Lifetime VIP Donor
Member
Nov 19, 2011
9,957
Portland, OR
CReynoldsMIZ said:
...he does know what he is doing. <------------> he's just kinda a putz and doesnt do things as thought out as i would...
One of these things doesn't belong with the other. :rotfl:

There's a reason they make special battery bolt ratchets with SHORT and INSULATED handles. The sparks from a short like that can contain tiny globs of molten metal, which are not pleasant to have embedded in your cornea. :eek:
 

CReynoldsMIZ

Original poster
Member
Oct 29, 2012
30
the roadie said:
One of these things doesn't belong with the other. :rotfl:

There's a reason they make special battery bolt ratchets with SHORT and INSULATED handles. The sparks from a short like that can contain tiny globs of molten metal, which are not pleasant to have embedded in your cornea. :eek:

What is the fun in that tho? Lol. I actually have a couple of those, but, its back at home 150 miles away with all the other tools. Only had a small craftsman socket set here with me I always keep in my car
 

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