The yellow wire on the power plug on a car stereo came unplugged and we are not sure if it goes in the last plug in or next to last

Hello .. Most likely someone has installed an aftermarket stereo and used the wrong power supply . Since the stereo and clock usually use the same power wire that's why its killing the battery . Theirs usually a red power wire and a yellow power wire on aftermarket stereos . The red goes to power with key on only and the yellow goes to power even with key off. the yellow just holds the memory so you dont have to set everything every time you shut the car off and on again and will only drain a very small amount from your battery. If the red and yellow are hooked to the same wire then that is the problem ....

Usually red is pos. goes to constant power source. Orange or yellow to keyed power source. Blue is for power ant. and matched wires are your speaker wires. Match these to yours cars wires. Oh black goes to ground.

Regardless of colour coding, please follow the following instructions (require multimeter):


Note: Attach multimeter earth wire (black) to the vehicle body. Convenient places may be the metal ignition barrel, the vehicle's car arial plug, cigarette socket body etc.


1) Testing for voltage with key out of the ignition, locate the permanent positive wire. This will wire into the yellow wire on your new stereo. The yellow wire circuit powers the stereo's memory.


2) Testing for voltage again. This time you are testing for a wire which only offers power with the ignition turned on. This one will wire into the red wire on your new stereo, and will power the unit only with the ignition on.


3) Now you know which your vehicle's positive wires are you can now test for an earth wire. Switch the multimeter to the resistance setting. There is one setting which will allow a buzzer to sound once you find continuity. With the ignition off test each wire until you get a buzz and a low resistance reading. This should be your earth wire. Double check this with the ignition in the on position. It should remain the same. If it changes to a positive with the ignition on and with the vehicle's lights switched on, then this is the dimmer feed for the stereo's screen. If you unintentionally found the dimmer feed, then you can ignore this wire, and search again for a wire which only offers an earth.


Now you have your power and earth wires located and can wire these into your stereo before continuing.


4) Next you need to use the stereo's balance and fade controls to allow only one speaker output to work from the stereo. So let's start with Left Front speaker output only. turn the stereo volume to mid way so that you can hear when you have connected to the right speaker. bare the remaining wires on the car side and test combinations of the remaining wires until you find the front left speaker of the car. Wire your stereo's wires once you find the correct connections.


5) Repeat the above steps with all remaining wires, remembering to adjust your stereo's balance and fade controls to only allow one speaker output at a time, to ensure the only one possible channel to work and help you identify which of the car's wires power the speaker you have selected.


Before re-assembly of the dash panel, check that your stereo and all functions work properly, being sure to use your fade and balance controls again to test all speakers individually.


If you want to be extra careful and wire the vehicle's speakers positive and negative, according to your stereo's outputs, not that this makes much difference on standard stereo arrangements, then follow this next step:


Make sure you can see the speakers themselves and connect a 1.5 volt AA or AAA battery to the speaker wires. If the speaker's cone pushes forwards, then the wire you connected to the battery's + terminal is indeed the positive wire and should be wired as such. If the speaker does the reverse, then you have the wires the wrong way around. Do not repeat this test for extended periods as damage may be caused to the speaker circuit.


Tip: Always solder all connections and insulate well from each other. Stereo connections can corrode over time and are prone to movement behind the dash. Poor connections may cause faults and low quality sound.

your adapter should be color coded to the pioneer wiring, orange, red and yellow are power feeds for igntion, 12 key and lighting, veryify voltage on the orange and red wiring to the radion with key on, the yellow is for radio lighting with parking or headlight operation, some adapaters may not have all the wiring and you may have to splice around the adapter.

next time by the wire harness that plugs it into the factory wire plugs never cut the factory plugs off you have wired something wrong you may damage something or start your truck on fire.

CAN I ADD AS AUX OR SOME WAY TO MY EXISTING STEREO? HOW?

Sure. The wire u are looking 4 is located in the bottom right side of the plug. Under the Bat (Red) and Ground (Black). On the last hole on the harness. Had same problem. Hope this helps you.

the power wire goes above a blue wire or next to (white/orange) and (green) in top row if there is a space there
yellow should be above black
(white/orange) should be above (blue/yellow) i think
than red over blue
hope this helps

should be next to or above yellow wire.
if not, re-post

no, this radio has no security code... Check to see that you have power on the yelow wire at all times, Power on the red wire when the key is on, and make sure the black wire is grounded well. something could have been disconnected at the paint shop.