How to test my radio? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**wancosc356** · 03-02-2010, 02:35 PM

I picked up a am/fm radio and I wanna test it without installing it. But I have a few questions.

There is a female plug on the back side. It looks like 3 prongs. I assume one is power, one is L speaker and one is R speaker wires. Am I right and if so, which one is which?

Also, aside from hooking up a speaker...can I just run a wire from my positive battery post to the radio power plug to test it? Do I need to ground the radio to the frame or anything?

Thanks.

cdowns · 03-02-2010, 03:13 PM

any 12v electrical unit needs a hot wire and a ground to complete the flow of electricity

**wancosc356** · 03-02-2010, 03:15 PM

Quote:

Originally Posted by cdowns

any 12v electrical unit needs a hot wire and a ground to complete the flow of electricity

Thats what I thought. Thanks.

TomJohnston · 03-02-2010, 03:49 PM

Chime in if I'm wrong, but don't those old OEM radios require a 10 ohm speaker? IIRC the output transister is germanium which can't handle the current output that a 4 ohm speaker will draw.

hayhauler71 · 03-02-2010, 04:54 PM

Quote:

Originally Posted by TomJohnston

Chime in if I'm wrong, but don't those old OEM radios require a 10 ohm speaker? IIRC the output transister is germanium which can't handle the current output that a 4 ohm speaker will draw.

8 ohm speaker is stock

**wancosc356** · 03-04-2010, 01:11 AM

Still need help on the plug....

Brad · 03-04-2010, 01:45 AM

One is power, one is ground and one is speaker. I'm sorry I can't help you more at the moment. Someone will be along shortly to tell you for sure....

**wancosc356** · 03-04-2010, 02:34 AM

Quote:

Originally Posted by Brad

One is power, one is ground and one is speaker. I'm sorry I can't help you more at the moment. Someone will be along shortly to tell you for sure....

I believe one is power and the two other would be speaker positive and negative. The radio gets grounded when it is bolted into the dash.

I just need to know which is which.

TomJohnston · 03-04-2010, 09:44 AM

This might help:

http://67-72chevytrucks.com/vboard/s...d.php?t=384992

hayhauler71 · 03-04-2010, 10:23 AM

I think it also stamped on the radio itself

gots2fish · 03-04-2010, 11:44 AM

Looking at the back of the radio. Left to right. Speaker grd, speaker, 12v.

**wancosc356** · 03-04-2010, 01:34 PM

Thanks fellas!

**wancosc356** · 03-04-2010, 08:00 PM

Quote:

Originally Posted by TomJohnston

Chime in if I'm wrong, but don't those old OEM radios require a 10 ohm speaker? IIRC the output transister is germanium which can't handle the current output that a 4 ohm speaker will draw.

Quote:

Originally Posted by hayhauler71

8 ohm speaker is stock

According to the shallow stamp on the top of the radio, it says
"DO NOT OPERATE
WITHOUT 8 TO
OHM SPEAKER"

I believe part of the stamp is worn out...

03-02-2010, 02:35 PM	#1
wancosc356 I Like Mine With No Shine! Join Date: Apr 2009 Location: SC Posts: 2,705	How to test my radio? I picked up a am/fm radio and I wanna test it without installing it. But I have a few questions. There is a female plug on the back side. It looks like 3 prongs. I assume one is power, one is L speaker and one is R speaker wires. Am I right and if so, which one is which? Also, aside from hooking up a speaker...can I just run a wire from my positive battery post to the radio power plug to test it? Do I need to ground the radio to the frame or anything? Thanks. __________________ Michael 1967 Chevrolet C10 Short Fleet (Literal Ground Up....One Day) 2006 GMC Sierra Crew Cab 4x4 1969 Lincoln Continental Coupe Project FOR SALE http://67-72chevytrucks.com/vboard/c...ct=4578&cat=17 1981 Honda CM400 C Bobber SOLD http://67-72chevytrucks.com/vboard/s...d.php?t=384152

03-02-2010, 03:13 PM	#2
cdowns Senior Member Join Date: Jan 2003 Location: daytonabeach Posts: 22,956	Re: How to test my radio? any 12v electrical unit needs a hot wire and a ground to complete the flow of electricity __________________ 71c-10 350/2004r/4:11 lowered3/4 longbed/dead by hurricane MEANING OF DEATH::::: SOMEBODY ELSE GETS YOUR STUFF DONT BELIEVE EVERYTHING YOU THINK TAKE MY ADVISE;I DON'T USE IT ANYWAY

03-02-2010, 03:49 PM	#4
TomJohnston Registered User Join Date: May 2009 Location: somewhere, MN Posts: 110	Re: How to test my radio? Chime in if I'm wrong, but don't those old OEM radios require a 10 ohm speaker? IIRC the output transister is germanium which can't handle the current output that a 4 ohm speaker will draw. __________________ Dad's 1970 Chevy C10 Custom 350, auto, armstrong power windows and doorlocks "My carbon footprint is bigger than yours"

03-04-2010, 01:11 AM	#6
wancosc356 I Like Mine With No Shine! Join Date: Apr 2009 Location: SC Posts: 2,705	Re: How to test my radio? Still need help on the plug.... __________________ Michael 1967 Chevrolet C10 Short Fleet (Literal Ground Up....One Day) 2006 GMC Sierra Crew Cab 4x4 1969 Lincoln Continental Coupe Project FOR SALE http://67-72chevytrucks.com/vboard/c...ct=4578&cat=17 1981 Honda CM400 C Bobber SOLD http://67-72chevytrucks.com/vboard/s...d.php?t=384152

03-04-2010, 01:45 AM	#7
Brad Out of the carpool lane. Join Date: Jan 2000 Location: Clark Co, WA Posts: 5,673	Re: How to test my radio? One is power, one is ground and one is speaker. I'm sorry I can't help you more at the moment. Someone will be along shortly to tell you for sure.... __________________ 1968 C-10 SWB, 5.7 Vortec/700R4/3.73 posi, Torch Red 1968 Camaro, 250/Powerglide, all original (No, I'm not gonna drop a 350 in it!...Jeez!) 2000 Honda VFR in the faster yellow! 2008 Husqvarna TE-610 1967 C-10 SWB 'Six Appeal'-Gone but not forgotten...

03-04-2010, 09:44 AM	#9
TomJohnston Registered User Join Date: May 2009 Location: somewhere, MN Posts: 110	Re: How to test my radio? This might help: http://67-72chevytrucks.com/vboard/s...d.php?t=384992 __________________ Dad's 1970 Chevy C10 Custom 350, auto, armstrong power windows and doorlocks "My carbon footprint is bigger than yours"

03-04-2010, 10:23 AM	#10
hayhauler71 Registered User Join Date: Aug 2009 Location: St. Paul MN. Posts: 1,996	Re: How to test my radio? I think it also stamped on the radio itself

03-04-2010, 11:44 AM	#11
gots2fish Registered User Join Date: Apr 2009 Location: Kearns, UT Posts: 9	Re: How to test my radio? Looking at the back of the radio. Left to right. Speaker grd, speaker, 12v.

03-04-2010, 01:34 PM	#12
wancosc356 I Like Mine With No Shine! Join Date: Apr 2009 Location: SC Posts: 2,705	Re: How to test my radio? Thanks fellas! __________________ Michael 1967 Chevrolet C10 Short Fleet (Literal Ground Up....One Day) 2006 GMC Sierra Crew Cab 4x4 1969 Lincoln Continental Coupe Project FOR SALE http://67-72chevytrucks.com/vboard/c...ct=4578&cat=17 1981 Honda CM400 C Bobber SOLD http://67-72chevytrucks.com/vboard/s...d.php?t=384152

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