Help Radio noise - The 1947 - Present Chevrolet & GMC Truck Message Board Network

aztxk5 · 03-02-2005, 02:55 PM

Has anyone ever experienced a noise through the radio that seems to be coming from the altenator? The more things drawing power the louder it is. The noise is a high pitched whine.

silvertonguedevil · 03-02-2005, 02:56 PM

If it's RPM related, you should be able to buy a noise filter for that.

farside847 · 03-02-2005, 03:24 PM

That reminds me of a funny story..... Once I had some odd radio noise and I thought the same thing, installed a filter and it was still there. Rewired the power but it didnt help. About a year later I replaced the antenna because the old one looked like crap and the entire wire had filled up with WATER! It had leaked in where the wire connects to the antenna and rusted up the inside. It made a nasty looking puddle on the garage floor. Put in a new antenna and wire and it worked like a champ!

Brewski* · 03-02-2005, 03:32 PM

Go to Radio Shack and get a noise suppression coil. Hook it to the positive wire to your radio. No Noise.

woodridge · 03-02-2005, 04:08 PM

Your might also have your alternator checked for a bad diode bridge.

aztxk5 · 03-02-2005, 08:12 PM

Thanks guys I will try both.

corn · 03-02-2005, 09:13 PM

Check for a "ground loop" before you buy anything. Make sure the antenna is grounded (at the cowl) good & the radio ground wire too. If your radio or your antenna dont have a good connection you will get a loop & get all sorts of noise. Is the radio a good brand or a cheapie? With some of the cheapies you will never get rid of it...corn

Alexis · 03-02-2005, 09:15 PM

are you running a amp?

cableguy0 · 03-02-2005, 09:15 PM

also dont forget crappy ignition wires or solid core ignition wires will cause radio noise as well

70 shorty · 03-02-2005, 10:21 PM

At first I thougt you were going to say you were listening to rap music.

aztxk5 · 03-05-2005, 10:17 AM

I'm not running an amp now, the radio is an older Kenwood. I don't listen to rap, but the ground idea is interesting. I hope to get a little Blazer time this weekend!
Thanks,
Al

Longhorn Man · 03-05-2005, 08:52 PM

I say you have an electricly 'dirty ground'. try moving the radio ground wire to another location.

shifty · 03-07-2005, 06:48 PM

If the noise becomes higher pitched when you increase your RPM's, it's typically "alternator whine". This is especially common in late-model imports and it most often due to poor or improper grounding of your stereo components

Alternator whine is caused by several things. The most common I typically ran into at the stereo shop I was working at were:
- When speaker wires or RCA lines cross power wires or other power equipment
- Ground loops, especially if your stereo is not grounded to the same place as your amp)
- Poor grounding ** (this is the most common cause)
- Insufficient power, or tapping power from an over-used power source

Any of these suggestions might help:

Start by checking yoru grounding.

Try to keep your ground wires as short as possible and make sure you adequately scrape paint to obtain a good ground. If possible, be sure to ground to the frame; a thing strip of metal isn't going to provide adequate ground.

Cheap speaker wires (18-24 gauge or smaller) is much more susceptible to EMI interference. The smaller and finer the wire is and/or the poorer and thinner the wire casing is, the more chance for noise and interference.

Look at Radio Shack for a 'ground loop isolator" or find one online.

There are some noise filters that can be purchased at Radio Shack and other places to help isolate your power line.

Never run any speaker or RCA wires parallel to power lines. If you must, keep them running together as short as possible

If you use a remote turn-on wire or power antenna wire, it can pick up interference to cause alternator whine.

03-02-2005, 02:55 PM	#1
aztxk5 Registered User Join Date: Jan 2005 Location: Azle, Texas USA Posts: 48	Help Radio noise Has anyone ever experienced a noise through the radio that seems to be coming from the altenator? The more things drawing power the louder it is. The noise is a high pitched whine.

03-02-2005, 02:56 PM	#2
silvertonguedevil Senior Member Join Date: May 2004 Location: Seaside, Oregon Posts: 1,789	If it's RPM related, you should be able to buy a noise filter for that. __________________ -Greg My Chevy trucks, past and present: 1962 C10 SB Fleetside 1964 C10 LB Fleetside BBW 1966 C10 SB Fleetside 1966 C10 SB Fleetside BBW 1968 C10 SB Fleetside 1971 C10 LB Fleetside 1971 C10 SB Fleetside 1972 C10 SB Fleetside Cheyenne 1972 C10 SB Fleetside Cheyenne Super 1972 C10 LB Fleetside Cheyenne Super 1974 C20 Cheyenne 1979 K5 Blazer Cheyenne 1982 K10 SB Fleetside Custom Deluxe 1982 K10 SB Fleetside Scottsdale 1986 C10 SB Fleetside Silverado 2008 Silverado 1500 4x4

03-02-2005, 03:24 PM	#3
farside847 Registered User Join Date: Feb 2005 Location: Bay Area, California Posts: 995	That reminds me of a funny story..... Once I had some odd radio noise and I thought the same thing, installed a filter and it was still there. Rewired the power but it didnt help. About a year later I replaced the antenna because the old one looked like crap and the entire wire had filled up with WATER! It had leaked in where the wire connects to the antenna and rusted up the inside. It made a nasty looking puddle on the garage floor. Put in a new antenna and wire and it worked like a champ! __________________ 1971 Chevy C10 Shortbed Stepside, 307v8 3-on-the-tree

03-02-2005, 09:15 PM	#9
cableguy0 Senior Member Join Date: Apr 2000 Location: Delta,Pa Posts: 14,950	also dont forget crappy ignition wires or solid core ignition wires will cause radio noise as well __________________ Owner of North Point Car Care in Dundalk Md. We specialize in custom exhaust on both modern and classic vehicles. We are a full service auto shop from classics to modern vehicles. Feel free to contact me with questions. I will give a 10% discount to any board member.

03-02-2005, 10:21 PM	#10
70 shorty Where's my beer? Join Date: Oct 2004 Location: Glen Allen, VA Posts: 1,768	At first I thougt you were going to say you were listening to rap music. __________________ 70 C10, shortstep, .30 over 250,Hurst shifted 3 spd parts hauler. Holley 390, Clifford Intake, Header, ported cylinder head, unknown bigger cam. 79 Corvette L82, 4 spd, black, red interior, headers, flowmasters, and unkown bigger cam. '03 Grand Cherokee Laredo, 4.0 4x4 daily driver. 165K miles, and runs great '08 Tahoe LTZ 4x4 155K

03-02-2005, 03:32 PM	#4
Brewski* Registered User Join Date: Aug 2001 Location: Rocky Mount, MO Posts: 1,293	Go to Radio Shack and get a noise suppression coil. Hook it to the positive wire to your radio. No Noise.

03-02-2005, 04:08 PM	#5
woodridge Senior Member Join Date: Feb 2005 Location: Maynardville, Tn Posts: 3,030	Your might also have your alternator checked for a bad diode bridge.

03-02-2005, 08:12 PM	#6
aztxk5 Registered User Join Date: Jan 2005 Location: Azle, Texas USA Posts: 48	Thanks guys I will try both.

03-02-2005, 09:13 PM	#7
corn Registered User Join Date: Dec 2003 Location: here Posts: 5,789	Check for a "ground loop" before you buy anything. Make sure the antenna is grounded (at the cowl) good & the radio ground wire too. If your radio or your antenna dont have a good connection you will get a loop & get all sorts of noise. Is the radio a good brand or a cheapie? With some of the cheapies you will never get rid of it...corn

03-02-2005, 09:15 PM	#8
Alexis Member since 2000 Join Date: Dec 2000 Location: Mountain View Ca / Mexico Posts: 7,879	are you running a amp?

03-05-2005, 10:17 AM	#11
aztxk5 Registered User Join Date: Jan 2005 Location: Azle, Texas USA Posts: 48	I'm not running an amp now, the radio is an older Kenwood. I don't listen to rap, but the ground idea is interesting. I hope to get a little Blazer time this weekend! Thanks, Al

03-05-2005, 08:52 PM	#12
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	I say you have an electricly 'dirty ground'. try moving the radio ground wire to another location.

03-07-2005, 06:48 PM	#13
shifty Questionable Join Date: Mar 2005 Location: Atlanta Posts: 13,376	If the noise becomes higher pitched when you increase your RPM's, it's typically "alternator whine". This is especially common in late-model imports and it most often due to poor or improper grounding of your stereo components Alternator whine is caused by several things. The most common I typically ran into at the stereo shop I was working at were: - When speaker wires or RCA lines cross power wires or other power equipment - Ground loops, especially if your stereo is not grounded to the same place as your amp) - Poor grounding (this is the most common cause) - Insufficient power, or tapping power from an over-used power source Any of these suggestions might help: Start by checking yoru grounding. Try to keep your ground wires as short as possible and make sure you adequately scrape paint to obtain a good ground**. If possible, be sure to ground to the frame; a thing strip of metal isn't going to provide adequate ground. Cheap speaker wires (18-24 gauge or smaller) is much more susceptible to EMI interference. The smaller and finer the wire is and/or the poorer and thinner the wire casing is, the more chance for noise and interference. Look at Radio Shack for a 'ground loop isolator" or find one online. There are some noise filters that can be purchased at Radio Shack and other places to help isolate your power line. Never run any speaker or RCA wires parallel to power lines. If you must, keep them running together as short as possible If you use a remote turn-on wire or power antenna wire, it can pick up interference to cause alternator whine.



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