AM Radio noise
#16
10-26-2005, 09:51 PM
Join Date: Apr 2005
Location: Longview, TX
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I remember a radio fuse on both panels. Pulling either stops the radio. Maybe the radio is on a separate circuit already. that circuit is different from the PCM circuit that is making the noise. The new capacitor is on the PCM circuit. Thinking about a possible bad connection to ground under the antenna...It works perfectly with key on Accy. So maybe that rules the bad antenna ground out. I really appreciate all the suggestions.
#17
10-26-2005, 10:42 PM
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See if this helps the problem. If it doesn't there are quite a few more pinpoint tests on my CD manual for audio problems.
Pinpoint Tests -- Sound System Quality
PINPOINT TEST J: NOISY RECEPTION, AM ONLY
² J1: CHECK ANTENNA CABLE CONNECTIONS
l Verify condition by operating radio chassis while engine is running, with vehicle in, or not in, motion.
l Check antenna cable connections including extension cable (if equipped).
l Are connections clean and secure?
Yes
GO to «J2».
No
CLEAN and/or SECURE antenna cable connections as required.
² J2: CHECK ANTENNA MOUNTING
l Check to make sure antenna is securely mounted to body at ground points.
l Are contacts clean and do they have metal-to-metal contact?
Yes
GO to «J3».
No
CLEAN and/or SECURE connections as required.
² J3: CHECK SUPPRESSION EQUIPMENT
l Check for presence of all required suppression equipment, radio frequency interference suppression bond and radio receiver hood bonding strap (if equipped) for security, cleanliness and metal-to-metal connection.
l Are connections OK?
Yes
GO to «J4».
No
REPLACE missing equipment and/or CLEAN connections as required.
² J4: CHECK MOUNTING AND CONNECTING WIRES OF FOLLOWING COMPONENTS
l Check the mounting and connecting wires of the radio voltage regulator capacitor (if equipped), radio ignition interference capacitor and radio interference capacitor for secureness, cleanliness and metal-to-metal contact. Refer to «Group 14».
Note: The capacitor mounting points are used to complete the electrical circuit and must be mounted securely to clean surfaces.
l Are connections OK?
Yes
GO to «J5».
No
CLEAN and/or SECURE connections as required.
² J5: CHECK OPERATION OF THE FOLLOWING COMPONENTS
l Check the operation of the radio voltage regulator capacitor, radio ignition interference capacitor and radio interference capacitor by replacing with known good components.
l Check generator by disconnecting wiring harness from voltage regulator.
l Verify radio chassis reception.
l Is noise eliminated?
Yes
SERVICE or REPLACE damaged components as required.
No
GO to «J6».
² J6: CHECK IGNITION WIRES
l Check ignition wires for proper routing, grounding and secureness of connections.
l Are wires OK?
Yes
GO to «J7».
No
REROUTE or REPLACE ignition wires or SECURE connections as required.
² J7: CHECK IGNITION SYSTEMl Check ignition system for proper operation. (Use Rotunda Distributorless Ignition System Tester 007-00075 or equivalent or check for open circuit ignition wires using ohmmeter.) Also check spark plugs for cracked insulators.
l Is ignition system OK?
Yes
GO to «J8».
No
SERVICE or REPLACE components as required.
² J8: CHECK CHASSIS MOUNTING POINTS
l Check all radio chassis mounting points for secureness, cleanliness and metal-to-metal contact.
l Are mounting points OK?
Yes
GO to «J9».
No
CLEAN and/or SECURE as required.
² J9: SUBSTITUTE ANTENNA
l Substitute a known good radio speaker and antenna, making sure to ground antenna base to an unpainted metal surface.
l Verify radio chassis operation.
l Is noise eliminated?
Yes
REPLACE or SERVICE radio speaker or antenna.
No
GO to «J10».
² J10: SUBSTITUTE ANTENNA CABLE
l Substitute a known good radio antenna lead in cable.
l Verify radio chassis operation.
l Is noise eliminated?
Yes
REPLACE radio antenna lead in cable.
No
GO to «J11».
² J11: SUBSTITUTE RADIO
l Substitute known good radio chassis.
l Verify radio chassis operation.
l Is noise eliminated?
Yes
Have radio chassis serviced at an authorized service center.
No
GO to «J12».
² J12: CHECK AMPLIFIER
l Substitute a known good radio amplifier (premium system only).
l Verify radio chassis operation.
l Is noise eliminated?
Yes
Have radio amplifier serviced at an authorized service center.
No
GO to «J13».
² J13: REPOSITION THE FOLLOWING COMPONENTS
l Check if noise can be eliminated by repositioning antenna, radio speaker or radio power feed wires away from other wires and/or brackets.
l Verify operation of radio chassis.
l Is noise eliminated?
Yes
REPOSITION permanently by taping.
No
GROUND various parts of the vehicle to the frame using a jumper cable. For example: engine, fenders, quarter panels, stone deflectors, air cleaner, body sheet metal. When noise is eliminated, PROVIDE a permanent ground where required.
Pinpoint Tests -- Sound System Quality
PINPOINT TEST J: NOISY RECEPTION, AM ONLY
² J1: CHECK ANTENNA CABLE CONNECTIONS
l Verify condition by operating radio chassis while engine is running, with vehicle in, or not in, motion.
l Check antenna cable connections including extension cable (if equipped).
l Are connections clean and secure?
Yes
GO to «J2».
No
CLEAN and/or SECURE antenna cable connections as required.
² J2: CHECK ANTENNA MOUNTING
l Check to make sure antenna is securely mounted to body at ground points.
l Are contacts clean and do they have metal-to-metal contact?
Yes
GO to «J3».
No
CLEAN and/or SECURE connections as required.
² J3: CHECK SUPPRESSION EQUIPMENT
l Check for presence of all required suppression equipment, radio frequency interference suppression bond and radio receiver hood bonding strap (if equipped) for security, cleanliness and metal-to-metal connection.
l Are connections OK?
Yes
GO to «J4».
No
REPLACE missing equipment and/or CLEAN connections as required.
² J4: CHECK MOUNTING AND CONNECTING WIRES OF FOLLOWING COMPONENTS
l Check the mounting and connecting wires of the radio voltage regulator capacitor (if equipped), radio ignition interference capacitor and radio interference capacitor for secureness, cleanliness and metal-to-metal contact. Refer to «Group 14».
Note: The capacitor mounting points are used to complete the electrical circuit and must be mounted securely to clean surfaces.
l Are connections OK?
Yes
GO to «J5».
No
CLEAN and/or SECURE connections as required.
² J5: CHECK OPERATION OF THE FOLLOWING COMPONENTS
l Check the operation of the radio voltage regulator capacitor, radio ignition interference capacitor and radio interference capacitor by replacing with known good components.
l Check generator by disconnecting wiring harness from voltage regulator.
l Verify radio chassis reception.
l Is noise eliminated?
Yes
SERVICE or REPLACE damaged components as required.
No
GO to «J6».
² J6: CHECK IGNITION WIRES
l Check ignition wires for proper routing, grounding and secureness of connections.
l Are wires OK?
Yes
GO to «J7».
No
REROUTE or REPLACE ignition wires or SECURE connections as required.
² J7: CHECK IGNITION SYSTEMl Check ignition system for proper operation. (Use Rotunda Distributorless Ignition System Tester 007-00075 or equivalent or check for open circuit ignition wires using ohmmeter.) Also check spark plugs for cracked insulators.
l Is ignition system OK?
Yes
GO to «J8».
No
SERVICE or REPLACE components as required.
² J8: CHECK CHASSIS MOUNTING POINTS
l Check all radio chassis mounting points for secureness, cleanliness and metal-to-metal contact.
l Are mounting points OK?
Yes
GO to «J9».
No
CLEAN and/or SECURE as required.
² J9: SUBSTITUTE ANTENNA
l Substitute a known good radio speaker and antenna, making sure to ground antenna base to an unpainted metal surface.
l Verify radio chassis operation.
l Is noise eliminated?
Yes
REPLACE or SERVICE radio speaker or antenna.
No
GO to «J10».
² J10: SUBSTITUTE ANTENNA CABLE
l Substitute a known good radio antenna lead in cable.
l Verify radio chassis operation.
l Is noise eliminated?
Yes
REPLACE radio antenna lead in cable.
No
GO to «J11».
² J11: SUBSTITUTE RADIO
l Substitute known good radio chassis.
l Verify radio chassis operation.
l Is noise eliminated?
Yes
Have radio chassis serviced at an authorized service center.
No
GO to «J12».
² J12: CHECK AMPLIFIER
l Substitute a known good radio amplifier (premium system only).
l Verify radio chassis operation.
l Is noise eliminated?
Yes
Have radio amplifier serviced at an authorized service center.
No
GO to «J13».
² J13: REPOSITION THE FOLLOWING COMPONENTS
l Check if noise can be eliminated by repositioning antenna, radio speaker or radio power feed wires away from other wires and/or brackets.
l Verify operation of radio chassis.
l Is noise eliminated?
Yes
REPOSITION permanently by taping.
No
GROUND various parts of the vehicle to the frame using a jumper cable. For example: engine, fenders, quarter panels, stone deflectors, air cleaner, body sheet metal. When noise is eliminated, PROVIDE a permanent ground where required.
#18
10-26-2005, 11:08 PM
The radio may have up to 3 power sources depending on how the unit is installed. 1 for constant power (radio station/clock memory) 2 for ignition source ( radio on/off with key) 3 dimmer ( radio dims when turning on headlights). I also didn't catch that this is not only an aftermartket radio but also a Kenwood. I worked in a stereo shop for a few years and engine noise was always a problem in Fords and seemed slightly worse with Kenwood. Still think finding a different ignition source could help but reading the above post reminded me that moving or adding grounds has helped also. Try running a ground from the radio straight to the chassis.
#20
10-29-2005, 06:25 PM
Join Date: Apr 2005
Location: Longview, TX
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It's better. Static is half gone. Just now getting around to doing what one of the first responders said. I'm working through the list. I popped the cap off the antenna, removed four screws and with much effort pulled the cable from the antenna. Everything looked bright and clean. After reassembly half of the static is gone. That was so much fun I think I will do it again with electrical cleaner this time then unscrew the antenna from base and clean those threads. Not having FM until high school, I remember the AM limitations well so I don't expect very much from AM. This is just tweaking it the best I can.
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