QuestionIn my 1996 Camry the radio display shows the AM/FM channel display but no sound comes out of the speakers, which had been working fine until recently. I checked the wiring harness which was connected properly. I assume that the built in amp is not working and purchased a untested replacement radio from a junk yard which did not work either. The guy at the yard said that the speaker fuse was probably blown. Does that vehicle have a speaker fuse? If where would I look for it. Thanks
AnswerHi Herb,
There's no speaker fuse, but some of these vehicles are equipped with factory amplifiers. In the Camry, most installers "bypass" the factory amp when installing a new head unit; it's very easy to do, because bypass plugs are available in the radio cavity. However, it's possible that your deck was installed with the factory amp integrated instead of bypassed. In this case, a problem with the factory amp would kill the sound.
If the new radio is connected to a single factory plug, then it's likely that the factory amp is still in the system. However, if it's wired through a two-piece plug, then either the vehicle wasn't equipped with the stock amp, or it has been bypassed.
If the factory amp isn't an issue, then the most likely cause is a shorted or grounded speaker wire, or a speaker with a shorted voice coil. Either condition would shut down a head unit's internal amplifier, resulting in no sound through any speaker.
You can try disconnecting all the speakers, then re-connecting them one at a time; see if there's one particular speaker that shuts down the output. Also, a multimeter can be used to test each speaker wire for continuity with the chassis metal (to check for a grounded speaker wire) and to test the DC resistance between the positive and negative wire of each speaker output. The resistance reading should be at least 3 ohms for each pair of wires; if you find a much lower reading, it's a sign of a shorted voice coil.
Hope this helps!
Brian
