radio whine

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radio whine

Post by eve23 » Sat Dec 04, 2004 1:36 am

what the best way to get rid of it???
a new relay?? a new distributor??

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Post by 330GT » Sat Dec 04, 2004 1:29 pm

Radio whines are usually caused by the alternator. If a diode is bad, then the power being generated has some A/C component rather than being mostly DC. In particular an alternator caused whine will vary in pitch as the engine RPMs change.

If the alternator checks out OK, there are filters available that are used on the incoming power lead to the radio. Check out Radio Shack or an auto sound place for the right kit.

A static noise that varies with the engine speed is usually something in the high voltage circuit to the spark plugs. Resistor plugs are the normal solution. However, on the older V-12s, the adaptor at the end of the wire is usually one from VW. These have a built-in resistor to solve the same problem. The kit solution is a capacitor installed on the distributor.

A kit will normally have parts to solve both problems. But V-12s have two distributors, so be sure and get the extra capacitor.
Regards, Kerry 330 GT Registry 250 PF Coupe 1643GT, 330 GT 2+2 8755GT, 308 GTS 23605

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Post by robsandiego » Sat Dec 04, 2004 1:58 pm

May I piggyback on your post and ask what about the radio loosing power when braking? Yes, when I brake, the radio blanks out and then comes back on shortly after releasing the brake pedal.

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Post by Jimmyr » Sat Dec 04, 2004 3:11 pm

Sounds possibly like a bad connection in the radio or power circuit. If the radio was added or has been removed there is a chance one or more of the ground wires may not be securly grounded. This is espically true at the antenna mounting point. If rust or an open cable shield on the antenna cable is found then clean the mounting surface or replace the cable, which ever is at fault. The previous described alternator and ignition faults will be greatly amplified if these grounds are at fault. Also, in the 330's there is a square junction block on the fuse panel where all of the 12 volt power leads are connected. These become corroded and can cause the problems of dimming or lack of power when another load, like the brake, is used. Clean all of the fuse contacts, as the radio may have been connected to one of these fuses also. Jim Riff

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Post by Ruedi » Sun Dec 05, 2004 9:04 pm

Whining: I agree that it is best to insert some kind of choke coil or suppression device in the power line to the radio. This should be as close as possible to the radio. There usually is a separate fuse for the radio in the power line. I recall kits that were inserted in this fuse clip. As suggested by 330GT, I would check with a stereo installation place or radio Shack.

Braking and radio shutting off: Unfortunately, the message isn't clear as to whether the problem occurs when the brake lights come on or only when braking leads to negative G-forces (i.e. using the hand brake instead of the brake pedals). Furthermore, it is unclear whether the radio shuts off or if only the antenna signal is lost. Here I have a couple of suggestions:

1. If the problem relates to negative G-forces leading to loss of antenna signal (radio lights staying on), trouble shoot the antenna mount as suggested.

2. If the problem relates to negative G-forces that shut off power to the radio, it originates most likely from a weak connection from a stabilizing bar behind the radio that was also used as ground contact or from a weak connection in the power supply line to the radio.

3. If the problem relates to the brake lights coming on, it is worthwhile checking whether the problem is a weak ground or a weak supply voltage. This test is easily done with a volt meter at the fuse inserted in the power line. If there is a significant drop in supply voltage, follow the line towards the fuse panel and see where the drop occurs. If the supply voltage is stable, check if there is any voltage between the radio enclosure and a known good grounding point. If such a voltage exists, you’re dealing with poor grounding of the radio.

Hope this helps.


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Post by eve23 » Sun Jan 16, 2005 12:58 pm

thanks for the help guys ...when the weather gets warmer....i will check it out....keep you posted...

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