AM/FM Factory Radio

Mopar_Gods · Aug 14, 2016

Noticed today driving the aspen I get quite a bit of static in all stations. Pulled the radio out to see if the ground strap was tight and it was. I also checked to see if the plugs were secured tightly and they both were. The Antenna appeared normal as well. Anyone else have this kind of issue when trying to listen to the radio stations??? Note the radio works perfectly when sitting but when driving the static is driving me nuts. I cant seem to get a clear station when driving. Here is a picture of the one I have. Thank You

BudW · Aug 15, 2016

There is a condenser (a capacitor) on one of the ignition coil wires, that is either missing or has a broken wire. Chrysler calls it a "Radio Suppressor"
It will be bolted to the ignition coil bracket at intake OR to Ignition coil bracket at firewall/fender (depending on where your ignition coil is mounted).

There could be a bad condenser/capacitor inside of the alternator – but I don’t see that one fail very often.

BudW

Aspen500 · Aug 15, 2016

I second what BudW said and add a question.
When you say it's clear when sitting but not when driving, do you mean sitting with the engine off or idling? Reason I ask is I've run into cases where the static wasn't engine speed related but vehicle speed instead. Somehow static electricity is generated by the tires rolling. Usually if that's the case, when you step on the brakes the static goes away because the brake shoes/pads create enough of a ground path to dissipate the charge. Normally only affects AM though. No, I am not making that up

Master M · Aug 15, 2016

Aspen500 said:
I second what BudW said and add a question.
When you say it's clear when sitting but not when driving, do you mean sitting with the engine off or idling? Reason I ask is I've run into cases where the static wasn't engine speed related but vehicle speed instead. Somehow static electricity is generated by the tires rolling. Usually if that's the case, when you step on the brakes the static goes away because the brake shoes/pads create enough of a ground path to dissipate the charge. Normally only affects AM though. No, I am not making that up

I have a car that acts the way you describe. I have static on AM and when I hit the brake pedal alot of the static goes away.

Mopar_Gods · Aug 15, 2016

Took a little sand paper and ruffed the connectors up a little. I still need to install my rear speakers. Sounds pretty good now he he

Leizurtime · Jan 19, 2017

I don't suppose anyone has an idea how to install this particular style of capacitor? It is the part that comes up for my car at part stores. BWD G82, STD RC11. My original has a wire connecting to the coil. Uncertain as to how I'm supposed to hook this one up.

Appears to be an "alternator capacitor." I'm guessing it mounts on the alternator, still no clue how to do it. Pep boys description states "OEM style connectors for precision installation." Can't seem to line it up to anything, perhaps the battery terminal and ground to the alternator body?

Even RockAuto says "Direct OEM Replacement" and it comes up under Radio Capicitor.

1977 PLYMOUTH VOLARE 5.2L 318cid V8 Radio Capacitor | RockAuto

BudW · Jan 20, 2017

Does this help?

I don't see this part failing that often.
If you have a rectifier diode burnt out, makes more sense, which basically overloads what that capacitor can compensate for.

Most cars have the capacitor for alternator (internal), another for ignition coil and a third one (on some years, not all) attached to back side of instrument cluster.
Also, non-resistor spark plug wires can cause electrical noise.

On many higher end models, there is also an electrical choke going to the main power feed to the radio, to also suppress electrical “noise”.

BudW

Leizurtime · Jan 20, 2017

BudW said:
View attachment 18792

Does this help?

I don't see this part failing that often.
If you have a rectifier diode burnt out, makes more sense, which basically overloads what that capacitor can compensate for.

Most cars have the capacitor for alternator (internal), another for ignition coil and a third one (on some years, not all) attached to back side of instrument cluster.
Also, non-resistor spark plug wires can cause electrical noise.

On many higher end models, there is also an electrical choke going to the main power feed to the radio, to also suppress electrical “noise”.

BudW

Yes, it does greatly. I just bought a new alternator, so I'm guessing I don't need this particular capacitor. Looks like I got the wrong one. Radio noise actually hasn't been an issue for me, even though I have installed an aftermarket stereo, with amp, and new front 3 1/2's & 6x9's. The capacitor on the coil is old though, the wire is cracked and looks like it might snap at anytime.

BudW · Jan 20, 2017

Is not that hard to access the alternator capacitor.
You have to first remove the alternator.
Remove both brushes.
Remove the case half bolts/screws.
Pull the two halves apart.
Remove the nut and screw holding it on – be aware of the insulators, or you could have a meltdown on your hands,
But both case halves back together, and tighten case screws/bolts.
Reinstall brushes – making sure there is at least ¼” of brush material remaining, first.
Reinstall alternator.

Note: I would highly recommend removing both rectifiers and test both (which can be done using a basic electrical meter/tester – but both need to be disconnected from each other and the stator, first). I suspect you have a bad rectifier bridge. If so, they are cheaper than an alternator is and not much more labor to replace them.

That said, I wouldn’t replace them unless verified bad, first.
BudW

BudW · Jan 20, 2017

If you don’t want the trouble to return it - then use it as a prank.

Take a piece of wire and touch one of capacitor to 12v battery (doesn’t matter which way), and touch wire to other end.

Then gently toss the “charged” capacitor towards a friend – who will attempt to catch the flying object.

They touch both ends of capacitor with their hand and ZAP, a harmless but attention getting discharge will occur.

Darth-Car · Jan 20, 2017

I have seen parts stores try to pass that part off as the radio noise suppressor that goes on the coil. Once again that is not the right animal, because the noise suppressor has a wire on it.

BudW · Jan 20, 2017

You might be able to modify it to work for the ignition coil.
I would want to make sure both have the same uF rating first. They are not hard to measure with most digital volt meters today (but not all will measure capacitors).

AM/FM Factory Radio

Mopar_Gods

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BudW

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Aspen500

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Master M

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Mopar_Gods

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Leizurtime

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BudW

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Leizurtime

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BudW

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