DVD plays but no sound. The radio always switches from FM to AM everytime you turn off the vehicle. Also the radio buttons on the steering wheel no longer function. Is this a bad radio unit? Or is

Which of these does your truck have ?
The Entertainment System on this vehicle is configured with a radio, antenna, and speakers.
The following list shows the radios available for this vehicle:
• Radio (UM7) - AM/FM with Cassette
• Radio (UB0) - AM/FM with CD
• Radio (UB1) - AM/FM, Cassette and CD
• Radio (UC6) - AM/FM, Integral Multi Disc CD Changer
Audio Amplifier
The audio amplifier is standard on some vehicle lines but is optional on most. The radio supplies low level audio signals to the audio amplifier in order to boost the signal sent to the speakers. The class 2 signal circuit allows the radio to recognize that an amplifier is present. Once the radio detects an audio amplifier, it will output low level audio signals. The audio amplifier is turned on when it receives a message via the class 2 serial data circuit indicating that the radio is on.
Digital Radio Receiver
The radio communicates with the digital radio receiver via the class 2 communications circuit. The digital radio receiver sends low level audio signals to the audio amplifier.
Steering Wheel Controls
Some audio functions are available using the steering wheel controls. The steering wheel controls consist of multiple momentary contact switches that connect a series of resistors. When a steering wheel control button is pressed, a specific resistance value is noted by the body control module (BCM). This results in a generated voltage, unique to the particular button. The BCM alerts the radio that the button has been pressed, and the radio responds, just as if the corresponding radio front panel button had been pressed.
Amplifier
The amplifier in early build vehicles is a class 2 device that communicates with the scan tool on the Class 2 bus. The Class 2 amplifier will set a U100 in the radio if there is a communication problem. The late build vehicles have a NON-Class 2 amplifier that does not communicate over the Class 2 bus and therefore the NON-Class 2 amplifier will not set codes. Both amplifiers have similar operating characteristics, therefore, there are not separate diagnostics for the NON-Class 2 amplifier.
Circuit Description
When the radio is powered up, the radio supplies low level audio signals to the speakers. If the vehicle is equipped with an audio amplifier, the amplifier will boost the signal sent to the speakers. The radio tests the speaker output circuits for a short to voltage or ground.
DTC Descriptors
This diagnostic procedure supports the following DTCs:
• DTC B1025 Audio Output 1 (Left Front) Circuit
• DTC B1035 Audio Output 2 (Right Front) Circuit
• DTC B1045 Audio Output 3 (Left Rear) Circuit
• DTC B1055 Audio Output 4 (Right Rear) Circuit
Reduced Volume - One or More Speakers
Step
Action
Yes
No

Schematic Reference: Radio/Audio System Schematics

1
Did you perform the Diagnostic System Check - Vehicle?
Go to Step 2
Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

2
Turn ON the ignition, with the engine OFF.
Turn ON the radio.
Adjust the radio balance and fade controls to each speaker.
Do all of the speakers operate properly?
Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems
Go to Step 3

3
Turn the ignition ON, with the engine OFF.
Adjust the volume level.
Test the appropriate speaker output circuits of the radio for A/C voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did the A/C voltage fluctuate with the audio output?
Go to Step 4
Go to Step 8

4
Turn OFF the ignition
Disconnect the radio.
Test the appropriate speaker output circuits of the radio for high resistance or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
Go to Step 9
Go to Step 5

5
Inspect for poor connections at the harness connector of the radio. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.
Did you find and correct the condition?
Go to Step 9
Go to Step 6

6
Inspect for poor connections at the harness connector of the appropriate speaker. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.
Did you find and correct the condition?
Go to Step 9
Go to Step 7

7
Replace the speaker. Refer to Speaker Replacement Reference .
Did you complete the replacement?
Go to Step 9
--

8
Replace the radio. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.
Did you complete the replacement?
Go to Step 9
--

9
Operate the system in order to verify the repair.
Did you correct the condition?

The blinker sound is through you door speaker. Need the radio to work properly to hear the blinker.

Where do you hear this creaking ? Steering column - inside the vehicle or out side the vehicle .

I would say the switches are at fault here, they work by a resistance value that is sensed and the appropriate function activated.

absolutely no idea ,do you have anything else plugged in that could cause the sound cut off although you say the radio works?or has a plug come loose in the back of the radio ,you could try one of them radio fitting centres as you never know some young lad comes out presses a button and it all works as you had the mute on or something but the radio works ,is it a built in cd player or a remote unit ? in my time a 8 track was the in thing these modern things are welll beyond your ancient dinasaur here .

The steering wheel mounted switches and the electrical contacts under the wheel are defective.

Try to find the horn and use a test light to try to ground out one or the other contacts. The horn should be energized at all times, as long as the battery is charged.

The horn should sound if you ground out one or the other terminal with a test light. If not, then the horn is bad.

Also, one can check the button at the steering wheel. If one uses a test light to ground out the switch there, the horn should sound.

See fig. 3 for wire for horn in steering wheel:

REMOVAL & INSTALLATION

Without Air Bag
See Figures 1, 2, 3, 4, 5, 6, 7 and 8
Disconnect the battery ground cable before removing the steering wheel. When installing a steering wheel, always make sure that the turn signal lever is in the neutral position.

1. Disconnect the negative battery cable.
2. If your vehicle is equipped with controls for the radio on the steering wheel proceed as follows:

Fig. Fig. 1: Pry out the control button assembly with a thin-bladed tool along the top of the edge, being careful not to damage the control assembly

1. Pry out the control button assembly with a thin bladed tool along the top of the edge of the assembly.
2. Disconnect the steering wheel control.

1. On vehicles without the radio controls on the steering pad, take a thin-bladed tool and pry the pad off the steering wheel. On wheels with a center cap, pull off the cap.

Fig. Fig. 2: Common steering wheel pad types

1. After lifting the trim off, pry the horn wires from the back of the pad. On some models gently push down on the horn lead and turn left, the wire and spring will then come out of the canceling cam tower.

Fig. Fig. 3: Carefully pry the lead wire for the horn off of the horn pad

1. Remove the retainer ring with a pair of ring expanders, then remove the steering wheel nut.

If your 3rd brake light always works, then the problem is the turn signal switch. To repair, you have to remove the steering wheel and air bag and replace the turn signal switch. If you have radio controls and or cruise controls on the steering wheel it will make a difference in which turn signal switch is the correct one. You will need some specialty tools to do this job such as a steering wheel puller and a compression tool and snap ring tools. Handling the airbag safely is very important, as it can severely injure you. If you have average or more mechanical skills, you can do it.

If the 3rd brake light does not always work, it could be a different problem.

1st.turn the dvd player on.then use the 'source' button on the left hand side of your steering wheel to find the"R.S.E.' setting on your radio.that's it.

Go to a scrapyard and buy a radio that comes from the same car you have, with the same steering wheel controls. The only difference will then be that the new one works. make note of any security codes and get vin# from vehicle radio was removed from so that anti-theft feature will not prevent it from working. Radio and wiring harness will not change if you obtain radio from identical vehicle.