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I'm hoping someone has their stock radio out and can verify this crazy wiring for me, as it just doesn't make sense, and it blows the fuse when I turn it on. The radio worked fine when I disassembled the car, and it was kept in a sealed container. Check out these pics.
That bare wire in the second pic MUST be a grounding wire and so it MUST(?) go to the center terminal in that plug. It would develop a dead-short to ground if it were connected to either of the outer two contacts.
Thanks for posting the pic, as it shows the exact wiring that I have. The first two pics I uploaded are of my radio, the pigtail pic is interweb. the red arrow in this pic clearly shows that bare wire coming from the copper plate and soldered to the far right terminal, understanding that your pic is showing the under side of the radio. I don't understand how that wiring is supposed work, as it causes a dead short. Guess I need to find a replacement radio, as I don't want to spend a bunch of money on a 50 year old radio.
That bare wire in the second pic MUST be a grounding wire and so it MUST(?) go to the center terminal in that plug. It would develop a dead-short to ground if it were connected to either of the outer two contacts.
It's hard to see, but there is another bare wire coming from the center terminal and soldered to the case, see attached pic (red arrow). It makes no sense to me
It's hard to see, but there is another bare wire coming from the center terminal and soldered to the case, see attached pic (red arrow). It makes no sense to me
It's not a short circuit- it reads about 16Ω. It's used as a RF shield back in the day. You will also notice the power wire inside the radio goes to a capacitor and the wire is coiled up- all to stop alternator/ignition noise.
The power terminal goes to dead short when I turn the radio on, and pops the fuse.
I'd try clipping that wire then- designed to stop noise on AM- probably won't notice a difference since spark plug & wire technology has changed the past 50+ years.
I'd try clipping that wire then- designed to stop noise on AM- probably won't notice a difference since spark plug & wire technology has changed the past 50+ years.
I ordered these last night from Classic Car Stereos. I really hope I'm not disappointed. I got 30% off for the radio and free shipping.
2 things to save you a bunch of frustration-
First-
Run a constant power and ground directly from the battery. I recommend 14GA wire and a 20A fuse right at the battery,
Going to the fuse box will give you "dirty" power- and you'll be chasing noise problems for days.
Using the yellow ignition wire OEM is fine as the radio pulls all its power through the constant power wire- it's not just for memory.
Second-
Small speakers aren't know for good bass response. However letting them have an "acoustic" short circuit -will make them sound really awful.
Both the front and back of the speaker are creating sound waves. However they are 180 degrees out of phase- and will actually cancel each other out.
More noticeable in the the longer wavelengths- like the bass. So any holes right next to the speaker should be sealed- I've seen dynamat used- 3M foil tape and silicone.
First-
Run a constant power and ground directly from the battery. I recommend 14GA wire and a 20A fuse right at the battery,
Going to the fuse box will give you "dirty" power- and you'll be chasing noise problems for days.
Using the yellow ignition wire OEM is fine as the radio pulls all its power through the constant power wire- it's not just for memory.
Second-
Small speakers aren't know for good bass response. However letting them have an "acoustic" short circuit -will make them sound really awful.
Both the front and back of the speaker are creating sound waves. However they are 180 degrees out of phase- and will actually cancel each other out.
More noticeable in the the longer wavelengths- like the bass. So any holes right next to the speaker should be sealed- I've seen dynamat used- 3M foil tape and silicone.
I understand this "Run a constant power and ground directly from the battery. I recommend 14GA wire and a 20A fuse right at the battery,"
But then you seem to contradict yourself with this "Using the yellow ignition wire OEM is fine as the radio pulls all its power through the constant power wire- it's not just for memory."
I have reading comprehension problems, so maybe you can clarify this for me
I understand this "Run a constant power and ground directly from the battery. I recommend 14GA wire and a 20A fuse right at the battery,"
But then you seem to contradict yourself with this "Using the yellow ignition wire OEM is fine as the radio pulls all its power through the constant power wire- it's not just for memory."
I have reading comprehension problems, so maybe you can clarify this for me
Got it- I have AADD- Adult Attention Deficit Disorder!!!
Your new radio has a ignition power and a battery/constant power plus a ground.
The ignition power wire on radio will just trigger the radio to come on. It will not use power from that source. So there will be no issue hooking up the new radio to the OEM yellow wire for ignition.
It won't get the dirty power.
Now the constant/battery power wire needs nice clean power for the radio- and that power will be the only source the radio uses. Commonly it has been called a memory wire- to keep the time set/radio stations.
But that is just not the case anymore. It supplies all the power .
Got it- I have AADD- Adult Attention Deficit Disorder!!!
Your new radio has a ignition power and a battery/constant power plus a ground.
The ignition power wire on radio will just trigger the radio to come on. It will not use power from that source. So there will be no issue hooking up the new radio to the OEM yellow wire for ignition.
It won't get the dirty power.
Now the constant/battery power wire needs nice clean power for the radio- and that power will be the only source the radio uses. Commonly it has been called a memory wire- to keep the time set/radio stations.
But that is just not the case anymore. It supplies all the power .
Richard
Seconded - easiest way I have found is just to run a new hot and ground straight off the battery up the center console. You can put a little inline fuse holder to sit in your battery box and know that wire is protected the whole way.
Got it- I have AADD- Adult Attention Deficit Disorder!!!
Your new radio has a ignition power and a battery/constant power plus a ground.
The ignition power wire on radio will just trigger the radio to come on. It will not use power from that source. So there will be no issue hooking up the new radio to the OEM yellow wire for ignition.
It won't get the dirty power.
Now the constant/battery power wire needs nice clean power for the radio- and that power will be the only source the radio uses. Commonly it has been called a memory wire- to keep the time set/radio stations.
But that is just not the case anymore. It supplies all the power .
Richard
So it's using a relay to to supply operating power.
From: Loud, Raw and Dangerous 1968 327 4S in Southern California
Since the radio only blows the fuse when you turn it on (and it worked before)....then I would suspect something has shorted out in the radio or the power amp module and likely not a wiring issue. Try disconnecting the power amp module and see if the issue goes away. The transistor may have shorted out.
So it's using a relay to to supply operating power.
Correct -relayed internally.
This was done years ago - It was to solve noise issues- and the new cars that had current sensing circuits that would not allow an aftermarket radio to pull any more current than the OEM one.
Robert currently has my 69 radio. Comes recommended. Only bad thing is he is back upped until February for repairs..
Worth the wait..he even told me why it was fried, and actually predicted my 10 amp fuse could not cause the issue….sure enough someone replaced it from 10 to 25..
way too many bad reviews on the resto units so glad isent this route…i would for sure ask for aux input be added or any other mods he offers ans still cheaper than Chinese replacement…
also he. Will recommend correct ohm replacement speakers if needed
Last edited by interpon; Nov 29, 2021 at 08:04 AM.
1971 Raido Power Wire HELP
