The speakers are not working at all. see a wire hanging from radio not connected to anything.

You only have 4 speakers, 2 at the front (L&R) and 2 at the rear (L&R). What you think might be Tweeters are just for show and don't exist. :>D

1999 Chevrolet Tahoe Car Stereo Wire Colors and Locations

the12volt.com https://www.the12volt.com > installbay > stereodetail
1999 Chevrolet Tahoe Stereo Wiring ; Right Front (-), Dark Green ; Rear Speakers, 6 1/2" Rear Doors ; Left Rear (+), Brown ; Left Rear (-), Yellow.

1999 Chevrolet Tahoe Car Radio Wiring Diagram

modifiedlife https://www.modifiedlife.com > 1999-chevrolet-tahoe-...
Our 1999 Chevrolet Tahoe radio wiring guide shows you how to connect car radio wires and helps you when your car radio wires not working.

How To Chevy Tahoe Stereo Wiring Diagram

My Pro Street https://my.prostreetonline.com > 2018/11/17 > how-to...

Nov 17, 2018 - Using this Tahoe wiring guide, you can wire up anything you need. Quickly identify speaker wires, amplifier outputs and even navigation systems ...
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If the guys who worked on your a/c had to work under the dash (which is necessary for some a/c components), they could have loosened a connection or damaged the speaker wire.

To check, try the following methods:

1) Remove the radio (search for instructions online), pull it out of the dash far enough to release the antenna and wiring connectors from the back (usually by pulling them straight out), then remove the stereo entirely. Then you can check the connectors and the wiring in the console for any obvious problems.

2) You didn't say which speaker quit working, but if the a/c guys had anything to do with it, it was probably one of the fronts. Check the wiring by removing any cover panels under the appropriate side of the dashboard, then sticking your head under the dash with a flashlight and looking for anything wrong with the wiring. IMPORTANT NOTE: Any time you're working under the dash, disconnect the car battery first to prevent accidental activation of the air bags.

3) Depending upon the age of the stereo, it is possible (though fairly unlikely) that one channel has gone dead. To test this while the stereo is out, you'll need to:

--provide power by running a wire from the positive terminal of the car battery to the appropriate terminal on the back of the stereo, which usually corresponds to a red wire on the connector.

--provide a ground in the same way, from either the battery's negative terminal or a known good ground point. The ground wire from the stereo is usually black (sometimes dark brown).

--provide a substitute pair of wires to the dead speaker (or any other car speaker you've got hanging around). Usually, each pair of speaker wires from the stereo is a wire of one color and another wire of the same color with a stripe (for example, purple and purple/white). Figure out those connections from the stereo, then connect the other ends of the wires to the speaker.

--turn the car key to "accessory," then turn on the stereo and see if the test speaker works. If it does, you know the problem is the wiring or connectors under the dash. If it doesn't, then the problem is the stereo itself.

--if the stereo doesn't turn on at all, it probably means that you've connected power to the "keep alive" terminal that keeps the radio's memory alive. Look instead for another brightly colored wire (often with an inline fuse, usually NOT blue), and try providing power to that terminal. Sometimes, a sticker on the stereo will show the proper electrical connections, or you could try looking online.

4) Or, you could call up the guys who worked on your a/c. First, ask them exactly what they repaired/replaced on your a/c, then ask if any of their work was under the dash. If they say yes, then tell them you think they screwed up your stereo wiring. If they admit that's possible, ask them to fix it themselves, or agree to pay the cost of a car audio installer to fix the problem, if the installer finds out it's probably their fault.

The following diagram shows a typical auto a/c system. The components usually found under the dash are shown at lower left. If the a/c guys repaired or replaced the expansion valve or anything related to the evaporator, that means they were almost certainly under the dash. (On GM vehicles, however, the expansion valve is often in the engine compartment, but the other components are similar to those shown here.)

Hey man, you have an amplified system. use a 70-1858 wiring harness and jump the blue/white wire from the aftermarket radio to the pink wire on the second plug. this will power on the factory amp with the aftermarket radio.

Chris-

One thing to remember about most radios, the RCA pre amp circuit will still work even if the mosfet power amp inside the radio does not. The best way to know if the amp inside the radio works is to use one matching color pair coming off the radio to wire up a random speaker right to the radio. You can use just about any old random 4 ohm speaker that is laying around to check it. The best solution if the amp inside the radio is blown is to replace the radio or amp the pre amp outputs with a small 4 channel amp. Oh, by the way. What vehicle are you connecting this into? And does the vehicle say Bose, Infinity, or ect sound or Premium sound? These usually denote a factory amplifyer already onboard and requires special connections to get the signal to these amps to then be delivered to the speakers.

If the balance feature on the radio does not change anything and all the wiring seems ok then the radio stereo itself may be bad.

Sounds like your Gr Caravan has the premium sound package. You likely haven't hurt anything - but you may need to modify the wiring a bit. The speakers have a tweeter speaker in the center of the main speaker and the wiring goes through that. However, it only worked with the premium package. Go in to the speakers and move the wiring connections from the tweeter to the main speaker. Your other option is to replace the speakers.

It sounds like they messed up your installation. You can confirm their work by verifying that each wire was attached properly.

2005 Pontiac Sunfire Car Radio Wiring Diagram Car Radio Battery Constant 12v+ Wire: Orange
Car Radio Accessory Switched 12v+ Wire: Yellow
Car Radio Ground Wire: Black
Car Radio Illumination Wire: Gray
Car Stereo Dimmer Wire: Brown
Car Stereo Antenna Trigger Wire: Pink
Car Stereo Amp Trigger Wire: Pink
Left Front Speaker Positive Wire (+): Tan
Left Front Speaker Negative Wire (-): Gray
Right Front Speaker Positive Wire (+): Light Green
Right Front Speaker Negative Wire (-): Dark Green
Left Rear Speaker Positive Wire (+): Brown
Left Rear Speaker Negative Wire (-): Yellow
Right Rear Speaker Positive Wire (+): Dark Blue
Right Rear Speaker Negative Wire (-): Light Blue

Click on this link for a PDF of the installation instructions of the radio (If you don't have the installation guide that came with the radio).

Illumination is the grey wire from the car to the orange with white stripe from the radio.

I suspect that the yellow wire from the car is not connected properly. When the orange wire (constant power from the car) is attached, but not the yellow wire you can insert and eject cds, but it will not turn on. Constant power is used for maintaining the clock and preset radio stations.

If everything looks correct, I would take your car back to the installer and have them correct the issue.

Check your connections again. Check that they're connected correctly. Look at a diagram, check the fuse on the power (red) wire from the radio. The radio might have fuses on the back of it, check them too. If anything put and tape every thing back together and use a harness then go from there.

Car Radio Battery Constant 12v+ Wire: Orange
Car Radio Accessory Switched 12v+ Wire: The radio harness does not provide a switched power source. Run a wire to the fusebox for switched power.
Car Radio Ground Wire: Black
Car Radio Illumination Wire: Gray
Car Stereo Dimmer Wire: N/A
Car Stereo Antenna Trigger Wire: N/A
Car Stereo Amp Trigger Wire: Pink
Car Stereo Amplifier Location: N/A
Car Audio Front Speakers Size: N/A
Car Audio Front Speakers Location: N/A
Left Front Speaker Positive Wire (+): Tan
Left Front Speaker Negative Wire (-): Gray
Right Front Speaker Positive Wire (+): Light Green
Right Front Speaker Negative Wire (-): Dark Green
Car Audio Rear Speakers Size: N/A
Car Audio Rear Speakers Location: N/A
Left Rear Speaker Positive Wire (+): Brown
Left Rear Speaker Negative Wire (-): Yellow
Right Rear Speaker Positive Wire (+): Dark Blue
Right Rear Speaker Negative Wire (-): Light Blue