• Welcome Visitor! Please take a few seconds and Register for our forum. Even if you don't want to post, you can still 'Like' and react to posts.

AM radio sounds terrible in 97 f150


ZMan

Forum Staff Member
TRS Forum Moderator
MTOTM Winner
TRS Event Participant
Joined
Jan 5, 2003
Messages
3,778
Reaction score
406
Points
83
Age
38
Location
Medina, Ohio
Vehicle Year
1992,1994
Make / Model
Ford Rangers
Engine Type
4.0 V6
Transmission
Manual
2WD / 4WD
2WD
Total Drop
4/4, bagged
My dads 97 f150 seems to be having a little trouble with the am radio. It is extremely staticy, and is affected by anything else electrical on the truck. Like if you have the blinker on it clicks, or if you roll the window up/down it makes an aweful noise. Its a factory cassette radio, has no problems with fm.
 


85_Ranger4x4

Forum Staff Member
TRS Event Staff
TRS Forum Moderator
Article Contributor
V8 Engine Swap
OTOTM Winner
TRS Banner 2010-2011
TRS 20th Anniversary
VAGABOND
TRS Event Participant
Joined
Aug 7, 2007
Messages
32,336
Reaction score
17,808
Points
113
Location
SW Iowa
Vehicle Year
1985
Make / Model
Ford
Engine Type
V8
Engine Size
5.0
Transmission
Manual
Sounds like a bad ground to me. :dntknw:
 

adsm08

Senior Master Grease Monkey
Supporting Member
Article Contributor
Ford Technician
TRS 20th Anniversary
Joined
Sep 20, 2009
Messages
34,623
Reaction score
3,613
Points
113
Location
Dillsburg PA
Vehicle Year
1987
Make / Model
Ford
Engine Type
4.0 V6
Engine Size
4.0
Transmission
Manual
2WD / 4WD
4WD
Tire Size
31X10.50X15
Try replacing the ignition capacitors. When they go bad the most noticeable symptom is frequently reception issues with the AM radio.

They are pretty cheap and easy enough to replace.
 

cody93

Well-Known Member
V8 Engine Swap
Joined
Mar 24, 2010
Messages
1,890
Reaction score
42
Points
48
Location
Duluth GA
Vehicle Year
1987
Make / Model
FORD
Engine Type
V8
Engine Size
5.0
Transmission
Manual
2WD / 4WD
2WD
yea, its capacitors for ignition or sheilding. AM radio is extremly supseptable to pulse fequencies, like ignition coils wich produce strong RF frequencies too.
 

Ranger SVO

Member
Joined
Aug 9, 2007
Messages
340
Reaction score
6
Points
18
Location
Abilene Texas
Vehicle Year
1993
Make / Model
Ford
Engine Size
2.3 Turbo
Transmission
Manual
Typically, when we have noise on AM, its an antenna problem. Check the antenna, make sure the base is mounted properly. The ground at the base of the antenna is where a majority of AM noise rejection takes place.

We would test this at the shop I worked at by temporarily hooking up another antenna and grounding it somewhere on the body. And 99% of the time, noise problem was solved. So the antenna got replaced.

One other thing I always did with AM noise problem was to ground the chassis of the radio to something metal on the vehicle.
 

shane96ranger

Well-Known Member
V8 Engine Swap
Joined
Oct 20, 2009
Messages
8,328
Reaction score
221
Points
63
Location
Utah
Vehicle Year
1997 / 1989
Make / Model
Ford F150-Stang
Engine Type
V8
Engine Size
4.6 Triton / 5.0
Typically, when we have noise on AM, its an antenna problem. Check the antenna, make sure the base is mounted properly. The ground at the base of the antenna is where a majority of AM noise rejection takes place.
OK..... just a question here. I've always understood that the AM antenna is internal, and the FM antenna is external. Have I had this misunderstanding for YEARS?
 

cody93

Well-Known Member
V8 Engine Swap
Joined
Mar 24, 2010
Messages
1,890
Reaction score
42
Points
48
Location
Duluth GA
Vehicle Year
1987
Make / Model
FORD
Engine Type
V8
Engine Size
5.0
Transmission
Manual
2WD / 4WD
2WD
for your pocket radios,alarm radios and boom-boxes and what not then yea, they have an antenae like this


but the one in your ride gets its input from the FM antenae also. dont believe me, go unplug your antenae from ur radio and see if AM works :)
 

adsm08

Senior Master Grease Monkey
Supporting Member
Article Contributor
Ford Technician
TRS 20th Anniversary
Joined
Sep 20, 2009
Messages
34,623
Reaction score
3,613
Points
113
Location
Dillsburg PA
Vehicle Year
1987
Make / Model
Ford
Engine Type
4.0 V6
Engine Size
4.0
Transmission
Manual
2WD / 4WD
4WD
Tire Size
31X10.50X15
go unplug your antenae from ur radio and see if AM works :)
That gives me an idea that I really should have had before.

Turn everything else in the truck off. The engine, the fan, the lights, all of it.

See if AM reception gets better. I have some shielding issues with the antenna cable on my B2. My capacitor is new but my FM reception, especially when at extreme range to the transmitter, gets much better when I shut the engine off.
 

Ranger SVO

Member
Joined
Aug 9, 2007
Messages
340
Reaction score
6
Points
18
Location
Abilene Texas
Vehicle Year
1993
Make / Model
Ford
Engine Size
2.3 Turbo
Transmission
Manual
Both FM and AM needs the antenna, only AM is really picky. AM or Amplitude Modulation works by by varying the strength of the transmitted signal in relation to the information being sent. The problem with this type of signal is that it is subject to interference. The vehicles computer, the alternator, the ignition can all interfere with the AM signal. Especially if the antenna shield is not properly grounded.

FM is a lot less picky. In a few show cars (no antenna), I've used just a piece of wire under the dash about 9 ft long. FM reception was perfect, AM was not. When we have an FM reception problem its usually a radio problem. Radio problem includes a good ground. Again, (back when I did installs), I always grounded the radio chassis to something metal on the vehicle.
 
Last edited:

ZMan

Forum Staff Member
TRS Forum Moderator
MTOTM Winner
TRS Event Participant
Joined
Jan 5, 2003
Messages
3,778
Reaction score
406
Points
83
Age
38
Location
Medina, Ohio
Vehicle Year
1992,1994
Make / Model
Ford Rangers
Engine Type
4.0 V6
Transmission
Manual
2WD / 4WD
2WD
Total Drop
4/4, bagged
Ya i should have added that, its fine with the truck turned off. So its a possibility something is wrong with the antenna?
 

Sponsored Ad


Sponsored Ad

Staff online

Members online

Member & Vendor Upgrades

For a small yearly donation, you can support this forum and receive a 'Supporting Member' banner, or become a 'Supporting Vendor' and promote your products here. Click the banner to find out how.

Truck of The Month


Shran
April Truck of The Month

Recently Featured

Want to see your truck here? Share your photos and details in the forum.

Follow TRS On Instagram

TRS Events

25th Anniversary Sponsors

Check Out The TRS Store


Sponsored Ad


Sponsored Ad

Sponsored Ad


Amazon Deals

Top