AM radio static

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midlifecuda

midlifecuda

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Without the car running my am radio works great but when the car is running I have static. The static does not seem to change pitch with the acceleration of the motor but it’s so bad it basically wipes out by very strong am station. What am I looking at here?
 
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Do you have something that looks like this on your ignition coil?
 
Did it ever work correctly?

If so what have you done to the car since then.

There is also a trim pot under the right tuner knob. That might help as well.

I suspect that you have either removed, or the various capasitors / condensers in the car (5 that I am aware of) are failing.

Also resister plug wires help a lot
 
Sorry, I got tied up since I posted. No I don’t see anything like that at either the coil or the alternator
 
Dana67Dart said:
Did it ever work correctly?

If so what have you done to the car since then.

There is also a trim pot under the right tuner knob. That might help as well.

I suspect that you have either removed, or the various capasitors / condensers in the car (5 that I am aware of) are failing.

Also resister plug wires help a lot
Click to expand...
 
There was an aftermarket radio in the car but I don’t recall if that worked or not, I was too busy enjoying the sound of the motor. I have now taken the radio back to a stock a.m. radio.
 
IIRC.

There is a capasitor IN the alternator.
One on the coil
One on the radio
One on the IVR
one in the dist.

The one in the dist is there to protect the points from burning.

I suspect the one on the IVR is for the same.

The one in the Alternator, on the coil and on the radio would be for noise suppression.
 
Yes to everything that has been said. Make sure you have quality resistance plug wires, add the condenser back to the coil, add an aftermarket noise filter (which is a coil and capacitor)to the radio power feed and trim the antenna. The AM static should be reduced to a tolerable level. If there is still a hum or whine you will need the alternator capacitor.
 
Thanks everyone. With regards to a condenser and the coil, where would that go? I am currently running an Accel coil and honestly don’t remember ever seeing a condenser by a coil. With regards to trimming the antenna, will this help with the noise while the car is running because again when the car is just on accessory mode the radio comes in fine without any static.
 
midlifecuda said:
Thanks everyone. With regards to a condenser and the coil, where would that go?
Click to expand...
IIRC plus side of coil to ground.

midlifecuda said:
With regards to trimming the antenna, will this help with the noise while the car is running because again when the car is just on accessory mode the radio comes in fine without any static
Click to expand...
Let's assume that the trimmer is adjusted so so. Without car running you get good enough reception. But with car running the static drounds out the so so tuning.

Adjusting the trim pot MIGHT bring in the station just better enough to overwhelm the static.

My guess is the lack of filters in the system from modifications.

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Are you really want to listen to AM radio?
There are many options to listen to music like retroradios, Spotify with your cellphone and a small JBL speaker. If you want listen good sounding music.
If the AM is definetly your gpal, do the work as the other guy have listed. Be sure your wiring is in good shape, clean also grounds and connectors.
Marco
 
Trim the antenna for max volume on any station above 1200kHz. Use a plastic or ceramic screwdriver. Don't twist or torque the adjustment. Half turn each direction is the range of adjustment.
The condenser suggestions are good things to try, but also your antenna could be the entire cause. If the coax shield is broken or the antenna ground at the fender is corroded you will be susceptible to radiated emissions.
 
I just wish there were more AM stations in my area.

One country, lots of talk and mexican music.

There was a rock and roll but they joined the 27 club
 
Dana67Dart said:
IIRC plus side of coil to ground.


Let's assume that the trimmer is adjusted so so. Without car running you get good enough reception. But with car running the static drounds out the so so tuning.

Adjusting the trim pot MIGHT bring in the station just better enough to overwhelm the static.

My guess is the lack of filters in the system from modifications.

View attachment 1715597251 View attachment 1715597253
Click to expand...
 
Of course my radio doesn’t have the trim screw under the base plate. The thought of removing the radio after all the work I’ve done in this car is making me sick to my stomach. But yes my goal with this car was to re-create a late 60s early 70s hot rod and I wanted to use the a.m. radio as I remember it as a kid. My parents never owned a new car in their life and for my entire life living under their roof they never owned an a.m. FM radio in their car. To play my regular music I will use a Bluetooth boombox in the backseat but for the look and theme of the car I am sticking with the a.m. radio, single speaker in the dash. I’ve gone through great length to achieve the look of hot rods from when I was a boy. The photo of the condenser on the coil is great, what condenser would I use for this application? I am assuming that the trimming screw is on the front of the radio and needs to be removed from the dash. It is a circa 1964/1965 Plymouth Barracuda /valiant/ radio. It actually says Valliant on the face. I believe the model number of the radio is 222.
 
Google the radio by number and then look at photos. You might see the trim pot.

I doubt it would be covered by anything other than a knob
so look at the rear of the radio.

Found this photo small hole by antenna port might be the pot?
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There is a number of ways static and noise can make it's way to any radio, AM, FM or CB/ ham, other communications

Bypass capacitors (radio noise condensers) are one. There should be a few. One is inside the alternator, another on coil +, another across the OEM instrument regulator/ limiter. There is normally one inside the radio hooked to the switched power in. If there is any doubt, you can "piggyback" one onto the rear / side of the radio, and splice into the red wire.

If your hood is not well grounded, ignition noise can radiate out through the cracks. There are various grounding schemes for the hood, including short loops of ground braid from the firewall to the hood, 1 on each side, allowing enough slack for hood open/ close.

Plug wires. Solid core / non suppressed plug wires WILL cause ignition noise. So can some ignition problems, AND THAT LONG WANDERING tach wire you through in through the firewall!!!!

Ever looked at most any Corvette? Know why they have that fancy metal junk covering the plug wires? Radio shielding........the car is plastic..............

And I don't know if it was mentioned^^ but a bad antenna/ antenna cable can cause problems
 
Again thank you all. I can’t seem to find anything on line about where the antenna trimming adjustment is on my radio. Also with regards to the condenser on the coil, is there a specific part number for small block mopar or are noise suppression condensers the same for all engines or other makes like a Mustang ?
 
Well I guess it’s all for not because this morning while having the gauge cluster out either the condenser on the back of the gauge cluster or something else started smoking because I guess it was grounding out to the dash frame and now my radio doesn’t work at all. I noticed that there is a 20 amp fuse in the radio slot and I’m sure it should be less so it didn’t protect the radio. I’m assuming I fried something in my radio. There is power going to the radio
 
Unless you crossed a speaker wire to a power connection, you did not hurt the radio. Generally, you have the speaker wires, the orange dial lamp wire, the red main power, and the case ground. Do you actually have power to the radio? I mean, did you check?
 
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