Power for aftermarket stereo

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73429mach

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Feb 1, 2011
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My Car
1973 Mustang Mach 1
1972 Mustang Mach 1 under construction
Can I get power to my aftermarket stereo thru the factory radio plug? The factory plug is a dual female plug. It has two white/pink wires and one blue/red wire. If I can, do I just use the plug with the white/pink wire or do I have to use both the white/pink and the blue/red?  RyanView attachment 41892

 
Light blue with red stripe is illumination.

White with pink is power.

Shane

 
I know this post is kind of old but, depending on what aftermarket head unit you bought, it may be pulling more amps than the old wiring/fuse was rated for. this is always true when installing an aftermarket amplifier. also, don't reuse the factory ground wire for an aftermarket head unit with bluetooth. if you do, I can almost promise you that the bluetooth will pick up your engine noise...it does sound like a supercharger when this happens, but you will not go faster. find a better ground than the one used in the old factory head unit.

 
I know this post is kind of old but, depending on what aftermarket head unit you bought, it may be pulling more amps than the old wiring/fuse was rated for.  this is always true when installing an aftermarket amplifier. also, don't reuse the factory ground wire for an aftermarket head unit with bluetooth. if you do, I can almost promise you that the bluetooth will pick up your engine noise...it does sound like a supercharger when this happens, but you will not go faster.  find a better ground than the one used in the old factory head unit.
My '82 Mustang used to make that noise when the stator in the alternator let go - high pitched buzzing through the speakers that used to rise and fall with the rpms.  I think Autozone gave me something like 3 alternators in the 2.5 years I owned the car - gotta love lifetime warranty.  LOL!

I went with a Retrosound Model 2 head unit in my '71, which is not drawing any more juice than the factory Philco AM/FM radio that came with it.  I did use the factory radio power lead, mostly because it had already been cut by the previous owner when they swapped in some aftermarket radio back in the '70s.  I did have to run a separate wire for the always hot memory power lead - maybe it distributes some of the power load to be drawn through that lead in addition to simple keyed power.  I think the ground wire is the factory ground as well - I only mentioned because the Model 2 is hands-free via BT, and I haven't heard a single 'out-of-place' noise through the speakers when using the phone.

For the 400 watt 2-channel amp for the subs, I ran a complete new circuit to the new fuse block I made for the aftermarket things I've added (I'm also a believer in not cutting into the factory harness any more than necessary).

 
I left the factory head unit in place and installed an 800w 5 channel amp. I'm running 2 rear 6x9's and a 12 sub. I use the RCA inputs to the amp to plug directly into my iPhone. I intend to install front speakers at some point once I figure out where to put them, and that is when I may install a head unit because I will need fader control. I may be able to get around this using the gain control to amp1 and amp2 on the amp, right now I'm running a bridged connection

 
Can I get power to my aftermarket stereo thru the factory radio plug? The factory plug is a dual female plug. It has two white/pink wires and one blue/red wire. If I can, do I just use the plug with the white/pink wire or do I have to use both the white/pink and the blue/red?  Ryan
Hi

i read the responses but didn’t understand...do you put a bullit plug with the new radio harness’ (constant) yellow wire and (Acc) red wire together in the female plug, leaving the light blue open? Your pic has the same female plug I have...so not sure what plugs into that or those openings

thanks!

 
Can I get power to my aftermarket stereo thru the factory radio plug? The factory plug is a dual female plug. It has two white/pink wires and one blue/red wire. If I can, do I just use the plug with the white/pink wire or do I have to use both the white/pink and the blue/red?  Ryan
Hi

i read the responses but didn’t understand...do you put a bullit plug with the new radio harness’ (constant) yellow wire and (Acc) red wire together in the female plug, leaving the light blue open? Your pic has the same female plug I have...so not sure what plugs into that or those openings

thanks!
Basically correct.  The white/purple lines are fused ACC power and can be used for radio power; the blue/red wires are for dash lamps and is typically not used in aftermarket radios.  You'll need to tap into a BATT fused line for any memory power lines; the cigarette lighter is nearby, handy and available to be tapped into.

 
Can I get power to my aftermarket stereo thru the factory radio plug? The factory plug is a dual female plug. It has two white/pink wires and one blue/red wire. If I can, do I just use the plug with the white/pink wire or do I have to use both the white/pink and the blue/red?  Ryan
Hi

i read the responses but didn’t understand...do you put a bullit plug with the new radio harness’ (constant) yellow wire and (Acc) red wire together in the female plug, leaving the light blue open? Your pic has the same female plug I have...so not sure what plugs into that or those openings

thanks!
Basically correct.  The white/purple lines are fused ACC power and can be used for radio power; the blue/red wires are for dash lamps and is typically not used in aftermarket radios.  You'll need to tap into a BATT fused line for any memory power lines; the cigarette lighter is nearby, handy and available to be tapped into.
Thanks midlife!!!

i have your handywork throughout my car, cluster harness, all harnesses restored, gauge harness...!!!  This really helps!

 
Can I get power to my aftermarket stereo thru the factory radio plug? The factory plug is a dual female plug. It has two white/pink wires and one blue/red wire. If I can, do I just use the plug with the white/pink wire or do I have to use both the white/pink and the blue/red?  Ryan
Hi

i read the responses but didn’t understand...do you put a bullit plug with the new radio harness’ (constant) yellow wire and (Acc) red wire together in the female plug, leaving the light blue open? Your pic has the same female plug I have...so not sure what plugs into that or those openings

thanks!
Basically correct.  The white/purple lines are fused ACC power and can be used for radio power; the blue/red wires are for dash lamps and is typically not used in aftermarket radios.  You'll need to tap into a BATT fused line for any memory power lines; the cigarette lighter is nearby, handy and available to be tapped into.
Hi again

the cigarette lighter (new part) didn’t work ( get hot) and I’m not able to get a reading on the little elbow plug so is there a better way to test it for power? Should I scrape it out maybe?The female spade end does have a reading on the meter....I’d like to use a tap splice to pickup power for the orange lead for memory... I have to use a larger bullit male plug on the aftermarket radio harness so it’ll engage the OEM (yellow) wire female plug. Thanks again for any advice!!

 
Your fuse for the lighter is probably blown or bad contacts at the fuse clips; rarely does the actual wire or plug fail. That said, many times that wire has been previously been cut and spliced back which can fail as well. Those are the two biggest reasons for no voltage at the cigarette lighter 90* plug (don't forget you need to find a good ground on the chassis to measure voltage!).

 
Your fuse for the lighter is probably blown or bad contacts at the fuse clips; rarely does the actual wire or plug fail.  That said, many times that wire has been previously been cut and spliced back which can fail as well.  Those are the two biggest reasons for no voltage at the cigarette lighter 90* plug (don't forget you need to find a good ground on the chassis to measure voltage!).
Ok did the check and there is voltage and it modulates between 8-14. So it seems to be hot.

ill plug it all back and check another lighter...

thanks as always!!

 
Your fuse for the lighter is probably blown or bad contacts at the fuse clips; rarely does the actual wire or plug fail.  That said, many times that wire has been previously been cut and spliced back which can fail as well.  Those are the two biggest reasons for no voltage at the cigarette lighter 90* plug (don't forget you need to find a good ground on the chassis to measure voltage!).
Ok did the check and there is voltage and it modulates between 8-14. So it seems to be hot

the unit is the USA -740 Custom auto sound

their instructions say to plug their red lead into the switchable power.. isn’t the switchable the one with two yellow and a blue for the radio?tuen it says to plug the yellow into a constant power for the memory

doesnt make sense because all the posts I’ve seen say the yellow lead goes to the OEM factory yellow. Anyway, I’ll keep trying
 
Yes, your red will connect to the red/yellow stripe wire. What color is the wire that you are measuring the fluctuating voltage on? Do you get voltage on it with the key off? It sounds like power from the instrument voltage regulator.

The lighter wire is light blue/ white stripe.

You can get the wiring diagram for your car by pulling down the Mustang Data tab at the upper right of this page.

 
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Yes, your red will connect to the red/yellow stripe wire. What color is the wire that you are measuring the fluctuating voltage on? Do you get voltage on it with the key off? It sounds like power from the instrument voltage regulator.

The lighter wire is light blue/ white stripe.

You can get the wiring diagram for your car by pulling down the Mustang Data tab at the upper right of this page.
No...red/yellow striped wires are RUN-only lines.  The white/purple line on the two pin Ford radio plug is switched (ACC) power; this line is what you're calling "two yellow" for some reason...

 
Yes, your red will connect to the red/yellow stripe wire. What color is the wire that you are measuring the fluctuating voltage on? Do you get voltage on it with the key off? It sounds like power from the instrument voltage regulator.

The lighter wire is light blue/ white stripe.

You can get the wiring diagram for your car by pulling down the Mustang Data tab at the upper right of this page.
No...red/yellow striped wires are RUN-only lines.  The white/purple line on the two pin Ford radio plug is switched (ACC) power; this line is what you're calling "two yellow" for some reason...
Hi gentlemen 

I have a feeling I’m not understanding what I have so I’ll post some pics tomorrow soothers can see and maybe be fit from your posts. Thanks!!

 
Yes, your red will connect to the red/yellow stripe wire. What color is the wire that you are measuring the fluctuating voltage on? Do you get voltage on it with the key off? It sounds like power from the instrument voltage regulator.

The lighter wire is light blue/ white stripe.

You can get the wiring diagram for your car by pulling down the Mustang Data tab at the upper right of this page.
No...red/yellow striped wires are RUN-only lines.  The white/purple line on the two pin Ford radio plug is switched (ACC) power; this line is what you're calling "two yellow" for some reason...
Hi gentlemen 

I have a feeling I’m not understanding what I have so I’ll post some pics tomorrow soothers can see and maybe be fit from your posts. Thanks!!
Ok this is a pic from a previous member’s post and the two pin female plug is like mine and yes the wires aren’t yellow but mine looked yellow. I know the blue wire is for illumination.

Q: do I plug the red from the radio harness in the two wire opening and then the yellow from the harness gets spliced inline with the cigarette lighter?

i was getting voltage from the two white and pink wires. I assume it was coming on when the key was turned on.

Q: does the new radio need to be attached to the dash via the OEM clip that slides in the dash? I assume that is ground and it needs grounding... I also will ground the harness to the dash.

Q: is there another place to tap into other than the cigarette lighter for the constant power source? Maybe in the fuse block? 

The cigarette lighter wires are untouched but the cigarette lighter doesn’t work so I’m assuming it needs replaced. I do get a reading from said wires on the meter so it must be a bad lighter as it doesn’t pop.

well sorry for all the questions and I hope I can get past this one!!!

thanks!!

T

 
As I said before, your main radio power plugs into the side of the 2 pin female plug that has two wires on that side (white/purple).

The memory power line can go to the cigarette lighter or tap into any of the bottom fuse clips on the fuse box. You can also tap into any green/yellow wires.

 
As I said before, your main radio power plugs into the side of the 2 pin female plug that has two wires on that side (white/purple). 

The memory power line can go to the cigarette lighter or tap into any of the bottom fuse clips on the fuse box.  You can also tap into any green/yellow wires.
Thanks for the simplified explain action sir!!

i still need to figure out why my cig lighter isn’t working... I’d like to use it as a phone charger.

r

 
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