I want to run new speaker wires to different locations but the speaker hook up on back needs a plug & wont allow me to just strip the wire & plug the wire in, can I get an adapter ?

Might be able to get an adaptor that plugs straight in painlessly.
Failing that it's the standard trace and identify method that eats time like crazy.

put the original radio back in. My guess is whoever installed the radio cut something they should not have.

Here are what the different colors do.1991 Ford F150 Truck Car Stereo Wiring Schematic
Car Radio Battery Constant 12v+ Wire: Green/Yellow
Car Radio Accessory Switched 12v+ Wire: Yellow/Black
Car Radio Ground Wire: Red or Black
Car Radio Illumination Wire: Blue/Red
Car Stereo Dimmer Wire: Orange/Black
Car Stereo Antenna Trigger: N/A
Car Stereo Amp Trigger Wire: N/A
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 (+): Orange/Green
Left Front Speaker Negative Wire (-): Black/White
Right Front Speaker Positive Wire (+): White/Green
Right Front Speaker Negative Wire (-): Black/White
Car Audio Rear Speakers Size: N/A
Car Audio Rear Speakers Location: N/A
Left Rear Speaker Positive Wire (+): Pink/Green
Left Rear Speaker Negative Wire (-): Pink/Blue
Right Rear Speaker Positive Wire (+): Pink/Blue
Right Rear Speaker Negative Wire (-): Green/Orange

1983 Chevrolet S10 Pickup Truck 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: N/A
Car Stereo Amp Trigger Wire: N/A
Car Stereo Amplifier Location: N/A
Car Audio Front Speakers Size: 4? x 6?
Car Audio Front Speakers Location: Dash
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: 4? x 10?
Car Audio Rear Speakers Location: Rear Corners
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

There may be extra wires you don't need. The basic set of wires on the radio is 4 pairs of colored wires--one black-striped and one plain for each speaker. Yellow is usually accessory power, red is hot, and black is ground. Some additional wires may be one for a power antenna, one for an external amplifyer, and one for facelight (in case it will run on dimmer)
The car should have the following corresponding wires:
Radio 12v--- orange
Radio Ground--- black
Radio Ignition--- yellow
Radio Illumination--- brown
Dimmer--- gray
Power Antenna--- pink (if you have one)
LF Speaker +/- tan - grey
RF Speaker +/- lt green - dk green
LR Speaker +/- brown - yellow
RR Speaker +/- dk. blue- lt. blue

The car or radio could have additional connectors, such as for a subwoofer, CD changer, etc.

fun fun fun.
1990 Toyota 4Runner Car Stereo Wiring Schematic
Car Radio Battery Constant 12v+ Wire: Blue/Yellow or Blue/Black
Car Radio Accessory Switched 12v+ Wire: Gray
Car Radio Ground Wire: Brown
Car Radio Illumination Wire: Green
Car Stereo Dimmer Wire: N/A
Car Stereo Antenna Trigger Wire: N/A
Car Stereo Amp Trigger Wire: N/A
Car Stereo Amplifier Location: N/A
Car Audio Front Speakers Size: 4′
Car Audio Front Speakers Location: Dash
Left Front Speaker Positive Wire (+): Pink
Left Front Speaker Negative Wire (-): Purple
Right Front Speaker Positive Wire (+): Light Green
Right Front Speaker Negative Wire (-): Blue
Car Audio Rear Speakers Size: 5 1/4′
Car Audio Rear Speakers Location: Side Panels
Left Rear Speaker Positive Wire (+): Black
Left Rear Speaker Negative Wire (-): Yellow
Right Rear Speaker Positive Wire (+): Red
Right Rear Speaker Negative Wire (-): White

Check this...

1992 Chevrolet Cavalier Car Stereo Radio Wiring Diagram
Car Radio Constant 12v+ Wire: Orange
Car Radio Switched 12v+ Wire: Yellow
Car Radio Ground Wire: Black
Car Radio Illumination Wire: Gray
Car Stereo Dimmer Wire: Brown
Car Stereo Antenna Trigger: Pink
Car Stereo Amp Trigger Wire: N/A
Car Stereo Amplifier Location: N/A
Front Speakers Size: N/A
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
Rear Speakers Size: N/A
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


Hope helps (remember comment and rated this).

Before I post this for you, I just wanted to let you know that you can buy an aftermarket harness that plugs right into your existing harness. Then it allows you to hook up to the wires without cutting your factory wires. They might even have it at Wal-Mart for less than $15. Anyway here are the specs. Don't forget to vote if this helped you out: Car Radio Battery Constant 12v+ Wire: Blue/Yellow
Car Radio Accessory Switched 12v+ Wire: Gray
Car Radio Ground Wire: Brown
Car Radio Illumination Wire: N/A
Car Stereo Dimmer Wire: N/A
Car Stereo Antenna Trigger Wire: N/A
Car Stereo Amp Trigger Wire: N/A
Car Stereo Amplifier Location: N/A
Car Audio Front Speakers Size: 5 1/4′
Car Audio Front Speakers Location: Doors
Left Front Speaker Positive Wire (+): Pink
Left Front Speaker Negative Wire (-): Purple
Right Front Speaker Positive Wire (+): Light Green
Right Front Speaker Negative Wire (-): Blue
Car Audio Rear Speakers Size: 6′
Car Audio Rear Speakers Location: Rear Door
Left Rear Speaker Positive Wire (+): Black
Left Rear Speaker Negative Wire (-): Yellow
Right Rear Speaker Positive Wire (+): Red
Right Rear Speaker Negative Wire (-): White

I dont believe its used in your situation .

here is a rundown

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 or ignition switch harness for switched power.
Car Radio Ground Wire: Black/White
Car Radio Illumination Wire: Brown
Car Stereo Dimmer Wire: Gray
Car Stereo Antenna Trigger Wire: N/A
Car Stereo Amp Trigger Wire: N/A
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

2003 Chevrolet Silverado 1500 Car Radio Wiring Diagram
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/White
Car Radio Illumination Wire: Gray
Car Stereo Dimmer Wire: Brown
Car Stereo Antenna Trigger Wire: Pink
Car Stereo Amp Trigger Wire: N/A
Car Stereo Amplifier Location: Under the center console.
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
If that dosnt match with your vehicle try this tip, 1st always find your speaker wires first,Since this is the most tedious part, its better to get those out of the way, 2nd thing Disconnect the battery of the vehicle so you don't blow fuses for the head unit, 3rd, strip back all of the wires that are available to you. Its better to grab the all together and cut them all an equal length to make it neat. 4th
Once you have all your wires stripped back - Grab any single wire. Hold it against a terminal on the battery and one by one go through and tap every other wire against the other terminal of the battery until you hear a "pop". When you hear a speaker popping, you have correctly identified the wires that run directly to it. If on the first attempt at popping a speaker you don't find one, pick up another wire and repeat the process. They will eventually come, and the more you identify, the fewer wires you have to mess with, You will need these Items,You'll need some wire strippers, a digital multimeter, electrical tape,9 volt battery