radio static after 6 to 12 volt conversion?


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By MG Cook - 13 Years Ago
Radio works fine when engine is not running but when engine starts I get so much static I just turn the radio off.

I know there's a way to overcome this static but can't remember, can someone help me out?
By gekko13 - 13 Years Ago
What sort of noise are you hearing?  Is it whining, rising and falling with engine revs or what?  More information is needed to identify the source of the interference.
By crown55vic - 13 Years Ago
First make sure hood is grounded. If brass spring is missing from cowl, you can run a length of wire from one of the hood mounting bolts to a good body ground point and see if that stops the static. Ben
By MG Cook - 13 Years Ago
Just a steady static noise like the power is cutting in and out.Plays fine with engine off so I am figuring it has to do with a ground problem.
By MG Cook - 13 Years Ago
Thanks, I'll try that.
By rick55 - 13 Years Ago
There are usually condensers fitted to components to stop the static. You need one on the battery post of the generator or alternator, another on power side of the coil and if using a generator another on the battery (B) terminal of the regulator. You will also need an inline resistor if using solid copper core spark plug leads. These you fit by cutting the coil lead and screwing the lead into the ends of the resistor. The newer spiral wound silicone leads don't need these resistors as they have resistance to overcome this interference.

I can't remember what size the condensers need to be but you should be able to pick them up at any parts supplier. If you have fitted an alternator it will create an unbearable amount of static as these are an alternating current device which has to be rectified to produce the direct current the battery needs. It'll howl like a banshee!

Generally speaking you cant have too many condensors.

Also from my experience, the older valve radios are much more tolerant of dirty power (interference) than the newer transistorised radios.

Hope this helps.

Regards
By junkyardjeff - 13 Years Ago
Is it the original radio or aftermarket.
By MG Cook - 13 Years Ago
Aftermarket, pioneer.
By Ted - 13 Years Ago

Is the static a whirring noise or does it more closely resemble a fast clicking?  I’m assuming the noise changes with engine speed?  If not, then that will point the cause into another direction.  The particular sound being produced will be a clue to what the major contributor is for the radio static.  You could have several combined sources for the radio noise including the distributor, spark plugs & wires, alternator, and loop grounds.  Still running solid core spark plug wires?  If so, then getting all the static out of the radio is going to be tough.  But a voltage filter on the power wire going to the radio should help overall.  You can also try another antenna as the shielded cabling on the existing antenna may not be doing its job.

By junkyardjeff - 13 Years Ago
I have a pioneer stereo in my 55 with no noise filters and no noises so far,right now it has a 351 and a late 70s alternator and regulator plus a duraspark ignition. Do you still have a generator and points.