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Location of Radio Noise Condenser in 69 Tbird

6K views 22 replies 4 participants last post by  OlDirty 
#1 ·
I want to change the radio noise condenser in my 69 Tbird, because when idling or accelerating, the old AM/FM Radio has annoying background noises in FM mode depending on the current RPM.
I already have a new capacitor laying here, but can't figure out where to install it. Hope you can help me?!
Thank you!
 
#9 ·
That is alternator noise. A few things will cause that. Bad ground in the fender antenna.
Bad ground in the radio case. Bad alt. radio suppressor. week F.M. signal. I think your
biggest problem is your 47 year old radio. What you are hearing is the A.C. hum from
your alternator before it gets to the rectifier. Your alternator is 3 PH. and it will sound like a high pitched whine. Well you know what it sounds like. Your radio has built in filter caps
that filter out that type of noise and i'll bet they are dried out and don't do their job. You
can take the power feed wire off the ignition switch and connect it directly to the battery.
That usually helps but you have to remember to turn off the radio when you shut off the
car or you will have a dead battery the next morning. good luck.
 
#11 ·
Yes, right. Worse gets to worse. Install a new radio. When we were kids some of us had
that problem and replacing the alternator fixed it. They have their own built in suppressers. Generators in the " old " cars were D.C. and didn't cause that problem. They also made a filter for that specific problem. It was the size of a C cell battery and about 4 inches long. Connected directly between the main alternator wire that came out the back of it and the battery. Kind of worked. I still say your main problem is your radio. You could replace all the filter caps. in it. They are usually 100mf - 220mf at 16 - 50 volts. Almost all after market radios and C.B.s are supposed to be connected directly to the battery and not the ignition switch. They forget to tell you that. Hope you get it sorted. Need any more help please feel free to contact me. Take care.
 
#13 ·
If I remember correctly that condenser goes inside the alternator across the negative and
positive rectifier bridge. That could also be the diode trio. I'm kind of thinking that is what
it is. Memory fails me. I've seen hundreds of those when I was on the bench and never
replaced one. Anyway that is installed inside the alternator.
 
#15 ·
Ford never made one. Your condenser is , was , found at part stores, electronic stores,
car stereo shops. Try finding a store that still sells C.B. radios. They might have what
your looking for. Myself, I haven't seen one of those in 50 years. They don't always work
but do cut down on some noise. If you have a scope you could connect it to the
alternator, find the frequency and get the proper cap. to filter out your noise but I
think your better off with a new radio. The new ones come with a built in suppressor
built into the power cable. Good luck.
 
#17 ·
check out after market replacement stores. Something like Summit Racing, but not them
themselves. Other shops specialize in replacement radios with the old school face plates
that have brand new guts. They are brand new up to date radios with the old school look.
You see these guys on Hot Rod T.V. all the time. Problem is I've never seen one for
a Ford radio but you never know. Or send your old radio out for repair.
 
#20 ·
If you decide to replace this condenser DO NOT loose or forget to install any of
the insulators on the + rectifier bridge. The large stud. If you do your alt will go
up like a roman candle and probably most of your wiring. When you put the brush
rigging back you have to load the brush holder or you will snap the brushes in half.
Don't loose the brush springs. They will go flying when you pull out the rotor.
Ford alts are not easy to work on. I don't like them. The rectifier bridge
and stator come out in one piece. Your stator stud will also have insulators so don't
loose them. That is the black one. Some are white. Do not over tighten when assembling.
You will break the plastic insulators. If that is the original alt your plastic insulators
are very brittle and could crumble to powder. Been there done that. Good luck.
 
#21 ·
Okay, I will NOT do that, because in case anything goes wrong, I won't get a replacement so fast, because of the fact that I'm living in Germany.
Next step is connecting radio directly to the battery, then I'll let you know the result.
Is there a simple black wire in the back of the radio, that I need to take?
 
#22 ·
Hard one to call. Your radio might have 2 wires on it not counting speakers. If ford stayed with their wiring code the power wire should be orange with black stripe. Some were connected to the headlight switch with a separate wire, some had one wire and the radio lit up at all times. Your radio might be set up with only one speaker. Maybe two. There also might be a wire for the power antenna if you have one. The power wire might be a bit thicker than the others. Your radio could have 7 wires, 5 , or 3 depends on how they wire the speakers. Power wire usually is the thicker and longer one. Could be black. Put a test light on the supposed power wire of the radio, turn the key on and off and see what happens. That will be your wire. That should be the only wire you have to move. Some
of those radios have separate grounds for the speakers. some grounded through the car
body and the radio case. There could be a ground wire from the radio connected to the
body. If you have a 4 wire speaker system ( 2 speakers ) remove the radio ground wire and connect it to the ground wires of your speakers. The radio grounds through the case and the antenna plug.
 
#23 ·
I just changed the capacitor in the alternator today. Was easier than I thought it'd be. Will need to change the brushes soon too.

Because of the fact, that I'm still rebuilding the Tbird and it's staying in the garage, I can't tell whether simply replacing the capacitor fixed the radio problem. But as soon as I can, I will let you know of course.
Just opened up another thread. Hope somebody can help me there too.
 
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