Skip to main content
Topic: radio noise on am (Read 1041 times) previous topic - next topic

radio noise on am

for a while off and on i have complained about am stations and static in my 20th since i got it 10 years ago.

i will list the symptoms and you all tell me what you think.



i slowly accelerate and shift through gears and there is some static.
i come up to driving speeds and the static is more intense  especially when it seems the engine is *not working hard*
i go into a left curve with chassis leaning a tad and there is static.
i go into a right hand curve with chassis leaning and all static goes completely away.
sitting still at idle in park there is normally static and moving steering wheel offers no change.
while moving it seems that if i step on the gas to go faster , the static is reduced by half,, but comes back as soon as the rpms are lower.
with the engine off and key in either the run or accy position, there is no static, so that helps isolate out things i think.
*i need to check for ac at the alternator.


I wiggle test connections at fuse box , starter relay and at the alternator with no luck.


i know on the 351 ford bronco 1990 that the coil has a filter capacitor,, what size is it?  a .5uf or what?  i have plenty of caps to chose from.

thoughts on a process of isolating the problem?


it almost seems like there is a wire harness/connection  "haning" somewhere that when it is tugged to the drivers side direction, the noise is gone yet its default "lean" is towards the pass side, meaning this answers why sitting still and rotating the wheel there is no affect.

im stumped, help me think through it.

radio noise on am

Reply #1
My 85 has a hood ground like this, I have heard that a poorly grounded hood can cause static.


radio noise on am

Reply #2
im gonna look at that here in a few.

interesting idea!  it does seem to offer as a culprit to some of the symptoms

radio noise on am

Reply #3
Quote from: bodyman;465233
My 85 has a hood ground like this, I have heard that a poorly grounded hood can cause static.


My 88 has that as well.

Check the radio ground. I had an similar issue on my 91 Mark VII (basically the same car). The radio ground was broken. Fixed that and the AM static disappeared.
88 Thunderbird LX: 306, Edelbrock Performer heads, Comp 266HR cam, Edelbrock Performer RPM intake, bunch of other stuff.

radio noise on am

Reply #4
In theory...everything from the factory *should* be enough to prevent static on the radio. The distributor wiring, alternator, coil, cap and rotor, spark plug wires, etc. were all designed to shield from interference. But I've seen shunts on a few cars, up near the distributor, that were likely installed at the dealership if someone complained enough. ;)

If the antenna coax is good and the radio ground checks out fine per Lou's suggestion, but you still get static, then you can get an inline noise suppressor and/or ground loop isolator at any car audio shop or even online. Most of the time they work great. Alternately, you can run your own radio ground to the metal cage surrounding the radio. I've had to do that in cars where the factory radio wiring was cut (the Dark Ages...before plug-in harnesses for aftermarket radios were invented).

 

radio noise on am

Reply #5
tinkering with the hood ground did nothing.
I integrated a .2uf, a .1uf and various other size caps and temp bonded into the coil like the stock ford trucks are.
this did nothing.

i will check my radio ground and follow up.

its really darn odd how when i go into a moving right hand curve though that the problem goes away