Need Help with a 12 Volt Entertainment System

[fcat700]

Do you know what the purpose of this electrical doodad is? Apparently it is a “Fuse filter” but what is its purpose? I have a camper with a 12 volt entertainment system, stereo, DVD and surround sound. Well it stopped working (was dead, no power) and I traced it down to a burned circuit on this doodad (the fuse was ok). I took the doodad to a TV repair man had he fixed the burned spot and said it also had a bad diode so replaced that as well. When I reinstalled the doodad and powered up the system it had power but the display was all messed up and the functions wouldn’t work, basically the buttons wouldn’t work and no sound. Today I took the doodad out and wired it without a doodad and the thing works great. So what am I going to have problem with if I just wire in a good old inline fuse? Thanks for you replies. PZ

 

[sjshaner]

Short answer is it is a noise filter as well as a fuse holder. If you put just a fuse inline the radio will work but you could get an alternator "whine" or a "popping" noise when the vehicle is running. I say could because if the charging system in the vehicle is working properly you shouldn't get any noise. The only time you would get the "whine" or "popping" noise is if there is poor shielding in the electrical system. If this is the case and you do get noise when the vehicle is running then just purchase a noise filter from Radio Shack or a car stereo store and install it in line with the power line after the fuse. Hope this helps.

By the way the reason why the radio didn't work when the tv repair man fixed the filter is that the choke (the large square component) was probably bad as well and wasn't allowing the proper voltage to pass to the radio.


The filter may have been damaged by a voltage surge caused by either a faulty alternator or bad voltage regulator in the vehicle. I would have the alternator and voltage regulator checked out in the vehicle. Some cars have voltage regulators built into the alternators and some have them exdternal and seperate. Autozone can test it for you free of charge. (At least the one by me can)

The filter could have just burned out for no real reason as well. It happens. I have had them go bad on me before for no reason.

 

[fcat700]

Great information sjshaner, Thanks! One thing I didn't say in the info was that this is a fifth wheel trailer. I'm sure that adds a lot of possible "voltage issues" to the possible cause of failure. I will make a trip to Radio Shack to get the proper replacement parts. Thanks again.