Cant find correct wire color code for my 2003 nissan frontier xe
If you do not know or can't find what each wire is in the factory stereo harness, you can follow these simple steps to determine what each wire is using a digital muti-meter and a AA battery or with just an analog meter. You may also need a 1 amp fuse and a few feet of 18-20 gauge primary wire.
First, with the ignition switch in the off position, test each lead for 12V+. If you are using an analog meter (my preference for this), set it to read DC voltage at or above 15 volts. Setting your meter below this could cause damage to your meter or at least blow an internal fuse. Attach the common lead to a known ground in the vehicle and probe each wire with the positive lead. Make sure you measure every lead in the harness even after you have found one that shows 12V + and record your findings. Typically you will only have one 12V+ constant wire in the harness, but some vehicles may have more. This will connect to the memory lead of your head unit, normally yellow on most aftermarket radios
Second, with the ignition switch in the off position, turn on the vehicle's parking lights and make sure the dimmer is turned all the way up, then probe every wire in the harness again that did not show 12V+ in the first step and record your findings. When you have found a wire that shows 12V+, leave your meter attached to the wire and adjust the dimmer to see if there is a change in voltage, then continue to measure the remaining leads. The lead that shows 12V+ with the parking lights on that does not show a change in voltage when you adjust the dimmer switch is the illumination lead. The lead that shows a change in voltage when you adjust the dimmer switch is the dimmer wire. Your head unit may or may not have a corresponding lead for either of these (typically orange and/or orange with white stripe on most aftermarket head units).
Third, with the ignition switch in the accessory position, measure each lead. You should find one that now shows 12V+ only when the key is in the accessory and run positions. This is the 12V+ switched lead or accessory lead and will connect to the red lead of most aftermarket head units.
Fourth, with the ignition switch in the off position, set your meter to read resistance at the lowest scale and zero out your meter if you are using an analog meter. Reconnect the common lead to a known vehicle ground and probe every lead that did not show 12V+ in the previous steps to find the ground lead in the harness. This will connect to the black lead on most aftermarket head units.
Fifth, turn the ignition switch to the accessory position and momentarily touch each lead to ground that did not measure 12V+ in the previous steps. The purpose of this is to find the negative power antenna trigger lead if your vehicle is so equipped. Keep in mind, most vehicles do not have a negative power antenna trigger lead, so if you do not find one, don't be alarmed.
Sixth, if you are using an analog meter, set it to measure resistance at the lowest scale and connect the common lead to any of the remaining leads that did not show 12V+ or ground in the previous steps. If you are using a DMM, set it aside and connect one side of the AA battery to any of these leads. Now connect each of the other leads, one at a time, to the positive lead of your analog meter or to the other side of the battery until you hear a popping sound from any of the speakers paying close attention to which speak is popping. If you can see the speaker when it is popping, pay close attention to the direction of cone travel. If it moves outward, you have the correct polarity for that speaker. When you have found a speaker, record the two leads for the respective speaker and set them aside. Continue to measure the others in the same manner until all speaker wires have been identified. If you are unable to locate any speakers in this step, you most likely have an amplifier. If you do not have an amplifier and have found all the speaker leads, but can not see them to confirm the correct polarity, don't worry, you can check this during the installation of the head unit.
t the installation you hear.
When you installing the speakers connect one at a time each speaker and listen it, if there is a distortion the polarity is wrong just switch the polarity and you here the difference, do it with the rest of the speakers.