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Chevrolet Avalanche Accessories & Modifications



  • jefishjefish Posts: 10
    I found one. The original guy at the car stereo shop was a dork. The second guy picked out the right mounting kit as well as the wiring harness.

    Here are some things I learned when replacing the stereo:

    1) Don't pull the mic grille off the headliner to see what color the mic wires are. Find another way. It took me 30 minutes to get the grille back on.

    2) The stock stereo has two plugs into the back, plus the antenna lead. The smaller of the two plugs seems to include the mic input as well as a few others. For a retail stereo to work, your remote turn-on (auto antenna) lead must be connected to the red wire on this second wiring harness. There may be a stock 4-channel amp in the Av, but I don't know where it might be.

    Now I just have to figure out a way to get a power lead from the battery, through the firewall, to the sub amp under the back seat. The firewall looks pretty tightly sealed to me.

    Anyway, I hope this is helpful.
  • ygmnygmn Posts: 179
    More info would be great. What size speakers did you find to fit the front and rear doors I did notice the front has seperate tweeter and the rear did not. What colors were the mic wires? I thought the Auto Volume was controlled by vehicle speed not a mic, well my 1999 tahoe was since I did not see a mic. I wonder if the mic is for onstar to reduce feedback when talking into overhead mic?

    How did you remove door panels? My front ones would not come off they were stuck near the just above and to the left of the door handle.

    Did you mount a sub Woofer and where? Does your amp interfere with the folding of the seats?

    I am considering contactin Gm about just buying the BOSE system they are using in the Caddy version. Any comments there?
  • I too would like to switch out the stock system in the Av for the Bose system in the Cadillac EXT. I know the Bose in the Caddy has 7 speakers as opposed to the 6 in the Av. The 7th speaker in the Caddy is a subwoofer which I would like to know where they put it considering it might not fit under the rear fold-down seats. Anyone know for sure? Also I would like to add the steering wheel radio controls of the Caddy if possible, so if anyone knows if this might work I would also like to know. I'm also curious where the amp is located for the Bose. Any info would be great.
  • I want this mod also.

    Jpendlum is working on putting together a kit for this setup. He has done this with other GM accessories. I'll keep you posted as to progress and price.

    Brad in SoCal
  • Thanks to all that have posted. I was wondering if someone has found a place to purchase GM accessories at a discount? It took me a few months to locate a Harley Davidson dealer that would sell parts at 20% off with no tax (if out of state). Most of those guys won't cut any kind of deal and all of that HD stuff is way over priced to begin with so any discount really helps. So surely there's some GM dealer out there who sells parts at volume.
  • ygmnygmn Posts: 179
    Try They are GM dealer and have great pricing online. shipping is where they make there money. The service is great and done strictly online to keep overhead low. I think if you scroll through the posts on care and maintenance you will see some other posts concerning them.

    Good LUCK and love the Avalanche!
  • jefishjefish Posts: 10

    I didn't replace the speakers in the front or rear doors, so didn't try to remove the door panels. The stock speakers actually sound OK once you get rid of the stock head unit. I may replace them at some point, but probably not for a while.

    There were three dark-colored wires coming from the back of the headliner mic. They are connected through the smaller wiring harness mentioned in my earlier post, but I didn't play with it any further. I'm pretty sure the mic is for the auto-volume function. Cruise along at a constant speed, then roll down the windows. The volume increases.

    I had a sub box built a while back for my Grand Cherokee. The box has 2 JL Audio 10" drivers inside, and I placed it right on the outside of the midgate. I haven't run the power wire to the amp yet, so I don't know if any sound will actually get through, but we'll see. I put the Phoenix Gold ZX600ti 600w sub amp under the rear driver-side seat. Fits perfectly, and does not interfere with the folding of the seats. I used one of the seat floor bolts as a grounding point. Again, I haven't found a way to get power to the amp, so I don't know if it's going to work very well.

  • jefishjefish Posts: 10
    1) When I hit the high beams on my Av, the low beams and fog lights turn off. I've noticed that you can partially pull in the high beam lever (passing lights) and all 4 headlights stay on (fog lights turn off). If you haven't tried this yet on a dark road, give it a shot. It's WAY brighter than the high beams alone. Is there a relay that I can switch out to make this the default?

    2) I'd like the fog lights to come on with the headlights every time. It's annoying to have to turn them on all the time. No, they're not necessary for normal driving, but they add a bit of light right in front of the hood. Plus, I think the truck looks better with all 4 lit up.

    Any ideas? #1 especially? Thanks.
  • about 3 weeks ago,I had a Flow Master Dual Exhaust System,70 series installed coming out both sides of the truck with Chrome square tips on both sides also. It looks and sounds awesome and really no interior noise at all. I LOVE IT. I
    was looking for a Radio with a in dash CD changer built in ? Does any one know of one avalible? Or just put in the Escalade EXT one.
  • txyank1txyank1 Posts: 1,010
    with that setup is that too many idiots don't know enough to turn those fog/driving lights OFF when they get in traffic. It's bad enough to meet them but it's also plenty annoying when they're behind you. When you're in the city with streetlights and all you don't need them!
  • cuss1cuss1 Posts: 17
    Hey invested, I'd like more details on your Flow Master. What is the FM model number? How much $? Slip on or need a shop to weld?

  • Hey CUSS1. I had the flowmaster 70 series put on as the are the queitest they have, and yes they had to weld the tips on and also weld it in the front near the converter. It cost $350.00! It was well worth it because they did a great job it was hard to get it to fit around the spare tire and brake lines to have it come out on both sides but it took them a while and it was done right. I stayed and watched. Next is to get factory chrome wheels done! If any one knows of a place to get it please let me know?
  • ygmnygmn Posts: 179
    Haven't read anything in a while from ya and was wondering how your steroe install went.

    I contacted OnStar and they said changing the head unit voids their warranty. All I asked them was how to wire it up with a different head unit. They were not much help.

    I am replacing the stock speakers in my AVY. Components front and rear doors. I will use double sided tape to hold the crossover inside the door.

    I have looked everywhere on the net and cannot find any stereo site that has any info on the AVY. I was trying to find the speaker harness since the wires are short in the door and I may want to re-install the stock ones IF I EVER SELL my AVY.

    Anyone do any stereo mods yet?? Info desired here!
  • ygmnygmn Posts: 179
    Today I am installing new speakers in my AVY.

    I am using Blaupunkt PCCI 650 in all 4 doors. Panels remove typical of a Suburban or Silverado.

    The stock rear speakers screwed in and the front mid range clip in. The front tweeters have a seperate wire which you should not use if planning to use the existing stock head unit.
  • cuss1cuss1 Posts: 17
    Let us know if you feel the speakers are a significant upgrade. I really like my AV, but feel the stereo is far below par for a vehicle with MSRP of $38,000.

    If a speaker upgrade makes a nice improvement, I would consider it. I am sensing the stereo also needs a serious boost in power to take full advantage of a speaker upgrade. Any advice on speaker upgrade, additional amplifier or complete replacement would be appreciated as it would make my AV "perfect".

    My wife drive a Jeep Grand Cherokee Limited(MSRP < $38K). It has an Infinity stereo with an Infinity amp all stock. It blows away the Chevy stereo set up. The steering wheel controls are also real convenient! I'd like to ultimately add steering wheel control to the AV.
  • cuss1cuss1 Posts: 17
    Have you folks checked out the AVs exhaust system? The output of the main muffler component comes out with a dual exhaust that then is combined down to 1 before coming out of the side.

    I have seen some posts about a full dual exhaust system (Flowmaster muffler was used I believe). If anyone has a photo of such a system, I would give it a try at my local muffler shop. The routing of the driver side of the dual looks like it may be tricky with the spare tire hanging down.
  • cuss1cuss1 Posts: 17
    Have you folks checked out the AVs exhaust system? The output of the main muffler component comes out with a dual exhaust that then is combined down to 1 before coming out of the side.

    I have seen some posts about a full dual exhaust system (Flowmaster muffler was used I beleive). If anyone has a photo of such a system, I would give it a try at my local muffler shop. The routing of the driver side of the dual looks like it may be tricky with the spare tire hanging down.
  • Hey CUSS1 go to the pictures section and click on my link to the pictures of my AV with the dual exhaust. It goes around the spare tire but it just takes a little time to do the job right.
  • Anybody out there bought and installed a GM grill guard for Avalanche yet? Is it setup for a winch?
  • txyank1txyank1 Posts: 1,010
    "full exhaust" you mean true duals including 2 mufflers. Or dual pipes out of a single muffler, which is pretty common. I spoke with Flowmaster before doing my Sierra and they do not recommend a true dual system. The new engines need a certain amount of back pressure which a true dual system reduces too much. End result is a loss of low end torque (as I've read here in Town Hall). I have a 50 series Flowmaster with a resonator, as the x-cabs tend to have a lot of interior resonance with this muffler, and duals out the back from the 1 in-2 out muffler. Couldn't say for sure it has more power but it sure sounds like it does!
  • Be very careful with the back pressure issue - Gibson makes a real nice single side swept - Nice growl - works well with 8.1L - presume the 5.3L would be just as effective - combine with headers and a K&N FIPK for a real nice truck.
  • ygmnygmn Posts: 179
    They are worth it very much. The ones I installed were components all around and there is a definite improvement. The stock head unit is fine and must be kept if you want the OnStar warranty to remain in effect.

    The rear speakers fit right in place and I surface mounted the tweeters in the top front of each rear door panel

    The front stock speakers use a large clip to hold speakers in place. I reused the bracket to hold the new ones in place. I then removed the stock tweeters from the plastic mounting bracket and drilled them out to hold the new tweeters.

    I strongly suggest it for anyone who wants better sound. An ampilifier was not required for good sound and I do not want to many modifications on the inside anyway.
  • jcody1jcody1 Posts: 58
    Just bought a 1500 Z71 with all the goodies. What an awesome truck! My only complaint so far is the less than diserable stereo, but like everyone else- I don't want to sacrifice the OnStar system. I am 99% sure the microphone mounted on the overhead console is for the OnStar system and NOT the speed sens. volume. All GM radios have that feature now and I have not noticed micrphone.

    Upgrading to the Caddy head unit would be my first choice if it offers CD changer capability. Does anyone know? Has anyone determined if the Avalanche has a factory amp? Is it behind the glove box? If we could determine which wires were the low level outputs (from the head unit)going to the amp we could at least upgrade the amp and speakers.

    It would be great if we could put our heads together and come up with a solution.
  • jcody1jcody1 Posts: 58
    according to Crutchfield. I called them and they said they have worked on one Avalanche so far. They suggested a four channel amp and new speakers. They confirmed OnStar WILL NOT work if you remove the factory head unit, and there are No aftermarket head units that support OnStar (yet).
  • ygmnygmn Posts: 179
    A person I know told me this by e-mail, "If you want to keep the OnStar there is a component made by SoundGate that will allow you to retain the OnStar system. It sells for about $150."

    I have no idea what it does but you may want to look into it if you want to change the head unit.

    I prefer to keep my factory head unit. Just my speaker change was enough for me. Guess I have bad ears.

    Good luck and welcome!
  • Hi, I am a newbie - have an Avalanche 2500 - 4x4 - 8.1L. I have read all of the problems and suggestions, still have many questions.
    I want this beast to really perform. To date I have:

    1. K&N FIPK - not bad, kicked it a little - tight fit on the cowl.
    2. Gibson single side cat back - nice sound - kicked it some more.

    On order:

    1. "The Other Guys headers" - 1/2" flange - should eliminate any problems.
    2. Yank 2600HD torque converter - should kick some more at the low end.

    Wish list:
    1. Whipple 8.1L Supercharger - after the new year - hope to see one in two weeks on another guys lucky truck.

    What else would you experienced guys reccommend?


    I have Mickey Thompson 16x8's - can only handle Firestone 265/75's because of wheel wells - tight as is. Don't want to raise suspension - but willing to take body up max 3" - will this help fit 285/75 Interco TRXUS. Will a body lift screw up towing [gooseneck excluded] - change bumper mounts?

    Thanks in advance for all thoughts, criticism, etc.
  • jcody1jcody1 Posts: 58
    Anyone interested in a power lock for your tailgate? I just installed a power lock actuator that is connected to the rest of the door locks so my tailgate is locked/unlocked whenever the doors are. It is quite handy. I also put in a pin switch on the tailgate- so whenever the gate is opened the cargo lights come on. New speakers and an amp go in as soon as I have some spare time. By the way- there IS an external STOCK amp. It is located behind the glove box. The OnStar system is connected to the amp and the head unit, so replacing either one of these items is not really possible unless you scrap OnStar. No an option as far as I am concerned. I am going to use a high->low level converter and connect my after market amp after the stock amp. Hopefully it will sound a lot better.
  • tip10tip10 Posts: 3
    JCODY the power lock and pin switch for the tailgate sound interesting.
    What actuator did you use (who made it , where's you get it??)
    How hard was it to gain access to the tailgate area??
    What'd you do for power to it??
    How long did it take to do the mod??

    Thanks in advance

  • jcody1jcody1 Posts: 58
    The actuator can be bought at any car stereo place like circuit city, tweeter, best buy...etc. I costs around 20 bucks. The cladding around the tailgate handle removes by extracting the two torx screws on the inside of the gate. It is the two screws furthest apart. I had to do some grinding on the fiber glass in order to get the motor inside the tailgate. It was a little bit of a challenge. I got power from the drivers door wiring harness found behind the dash side panel cover. It is polarity reversing. The whole mod only took me about 5-6 hours, but I am fairly experienced with these sort of things. If you want more specific info let me know- I don't mind at all!
  • tip10tip10 Posts: 3

    I've done similar things on other vehicles -- was just after a quickie answer as to the "degree of difficulty" since I'm at work -- I'll probably nose around the beastie this weekend and take a look at it.

    Appreciate the response!!
This discussion has been closed.