Common problems include:
1984-1989
- Amplifier Failure
- Speaker Relay Failure
- Head Unit Problems
- Poor Radio Reception
1990-1996
- Amplifier Failure
- Speaker Relay Failure
- Head Unit Problems
- Receiver Failure
- Poor Radio Reception
Listed below are common symptoms and solutions to the above problems.
1984-1989
Amp Failure
No sound from individual speaker box or popping, squealing, hissing sounds and no music.
Solution: Replace amp unit (units should be replaced in pairs to maintain sound compatibility).
There are correctly remanufactured Bose Amp Units under part number. There are correctly remanufactured Bose Amp Units under part number 614674.
1984-1985 Corvette Front BOSE Radio Amplifier, Part Number: 614674
Speaker Relay Failure
A loud “pop” is heard when radio is turned on. Battery usually drains overnight.
Solution: Replace relay with part number 604099. The relay is located under the right dash, attached to the brace to which the turn signal relay is also attached.
Head Unit Problems
Deck won't take tape cassette or spits it right back. Unit needs to be remanufactured. Delco used an expensive Blaupunkt Deck in these units.
Solution: See part number 665017
1984-1989 Corvette Radio Restoration Service, Part Number: 665017
Poor Radio Reception
May be due to a faulty antenna. The 1988-1989 factory style antennas were the best units made before the 1984-1987 Corvettes and can be retrofitted.
Solution: Replace the power antenna assembly with a factory style replacement. For 1984-1987 Corvettes, 1988 and newer power antennas can be retrofitted for a more reliable solution.
1990-1996
Amp Failure
No sound and or a popping, squealing hissing sound.
Solution: Replace the amp where the strange sound is coming from. We suggest Amps being replaced in pairs, i.e., 2 front or 2 rear. In addition, most 1990 Y Cars (Corvette) will need a separate adapter harness as GM used an early design Amp similar to the 1984-1989 amps.
Amps are Amps! Right? WRONG! You MUST use only Corvette Bose Amps. Aftermarket amps are of lesser quality and do not match the OEM Bose Sound and cannot duplicate it.
From 1990-1996 Corvettes used 4 different amps (front or rear and coupe or convertible). The convertible used a slightly louder amp. These new amps incorporate better technology and will last much longer than the originals. Used amps are almost never successfully repaired.
Speaker Relay Failure
A loud pop is heard when the radio is turned on. Battery usually drains overnight.
Solution: Replace relay with part number 604099. The relay is located to the right of the steering column under the dash (1990-1992) or in the right rear storage compartment (1993-1996).
1984-1989 Corvette Bose Amp Electric Relay, Part Number: 604099
Head Unit Problems
Deck will not take a CD / Cassette or show “ERR” on the display.
Solution: The unit needs to be remanufactured. See part number 665021. All 1990-1991 units used an early design CD deck and can be upgraded. The head unit does not contain the actual radio unit.
1990-1996 Corvette Radio Restoration Service, Part Number: 665021
Receiver Failure
If there is no sound from any speaker and no radio operation then the radio receiver may have failed. You should check both fuses before going further into the problem. The receiver is under the right dash panel (1990-1992) or in the right rear storage compartment (1993-1996).
Convertibles also used the storage well behind the passenger seat and are especially prone to water damage.
Poor Radio Reception
Solution: Replace the antenna, which is the most likely problem due to poor grounding. We also suggest replacing the entire assembly, as the repair kits may not always solve the problem.
Bose Speakers - All C4 Units
In the past, most speaker problems were due to failed amps. However, due to age and heat, speaker cone failure is now possible. This symptom would be a sound like paper rattling and is different than an Amp sound. You must use a Bose speaker for proper operation of your system. Failure to do so could short out the amp and cause overheating to the point of a fire! We know of no aftermarket speaker that has the correct OHM impedance to match the OEM Bose Speaker.