where do i connect hu ground wire?

i need help understanding where to connect the black ground wire for my head unit ?,        i just don't understand if i just simply connect all the colored wires from the pioneer harness to the wires on the harness adapter, which connects to my stock harness ?   (including the black ground wire)?        or do i not connect the black ground wire to the harness, and instead just connect the black ground wire coming from the pioneer harness directly to the metal chassis of the car ?

cause it says in the manual for the head unit says to connect ground wire to metal part of cars chassis,   but does that mean run a new ground wire from some part of the head unit to the chassis ?    and still connect the black ground wire from the pioneer harness to the other harnesses with all the other color wires matched up ?   

any help would be appreciated,   thanks

What kind of vehicle? Is the wire on the harness solid black or black with a white stripe?

Some vehicles do not have a ground wire in the harness. If the wire is solid black, ground the radio there. If it is a black with a white stripe, it is a ground reference for a factory amplifier. If that is the case, you will need to ground it to the chassis, or the framework that the factory radio was mounted to.

sorry, its a 90 honda crx, the wire on the harness is solid black,

other people online say its better to ground to chassis, cause you can be sure its good and think its better if the ground is closer to the head unit itself too i heard ?    would'nt it be better doing that ?

cause i don't know how good the stock harness ground is ?   not even sure where the stock ground is at ?     since its old, it could be a loose connection ? from all the vibration of years of driving?   

i think you are worrying a little too much on this ground question. it really is not as serious as you are making it out to be. the biggest problem you have is the fact that your factory radio plug has been cut off, this makes it hard because you will need to test and verify every wire you are trying to hook up to the new radio.

you will probably not use every single wire that you have available either from the radio or from the car, an example being the illumination wire, your car has this wire but your new radio does not so just cap it off and leave it alone. that example is why it is important to test and verify the function of each wire because it would be bad if you accidentally hooked up the illumination wire straight to a speaker output it might hurt the new radio. if you dont have a voltage meter that also measures ohms too then i would take it to someone who does and have them install your stereo. i would not be saying this if you still had your factory wire harness.

yes it is usually just as good if not better to make a brand new ground when you install a new radio in a car that is the same size wire as the power wire, usually a factory ground will be smaller although this doesnt really cause any issues. newer radios dont really use that much power so its fine if the ground is a little smaller, it only really starts to matter when you are dealing with a big radio with a screen and larger internal amp.

you can use almost anything that is made of metal in that car as a ground as long as it is bare unpainted metal. use a self tapping screw and a ring terminal to make a solid connection and you will be just fine.

Connector cut off eh? This might help you; https://www.the12volt.com/installbay/forum_posts.asp~TID~74637~PN~1

Always check the hot topics forum for good general tips.

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i usually always sound like i'm over worrying about things, partly just cause i'm going over all the little details, to make sure i'm covering everything correctly.

i have a couple charts showing the typical wire colors from the factory crx wiring harness, compared to what wire colors match to most newer stereo wiring harnesses.

so far i was able to match up all the wires to the stock harness, i just did'nt understand what the white wire with green stripe was for yet?,   there was a white wire with a blue stripe also, and on the wire chart it says the wire for 12volt battery is either white with yellow stripe or white with blue stripe?

on the reverse wire harness, one wire is labelled "12volt memory" and another wire labelled "12volt power", (the red and yellow wires),   but what does "memory" mean ?   i thought one should be for power/batter ? and other for ignition ?   would the one called "12volt power" be the one for battery?    and the one called "memory" the one for ignition?    just need to understand so i can know which ones to connect and match up to the wires on the stock harness, cause these are the only ones i have left to do in order to finish it

i realise i don't need a super ground just for using a simple setup like mine with just head unit and stock speakers, i guess im used to how it was on my previous setups, which had amps and a sub, it had a thick ground wire coming from back of head unit to a sanded metal spot on the chassis, but the main reason i had it grounded like that was cause i had an alternator ground noise problem, and someone told me to try putting ground from head unit to chassis, and i looked to see how the install shop had it, and they just had the ground wire attached to a metal bracket behind the center console, but wasnt good enough, cause after i switched the ground wire to the chassis, the ground noise totally went away.

but since im not using amps or anything this time, i guess i dont have to ground it to the chassis, but might be good in case i decide to add an amp or sub later on and not worry about ground noise again.

and DYohn,   thanks for the link, i did look at the hot topics forum but must of missed that one, i'm about to read it

the "memory power" is the yellow wire on the new radios harness and it should go to a constant 12v power source. this is probably the WHITE/ blue wire you found. the red "12v power" goes to a wire that changes to 12v when you turn the key into the on position. this wire tells the radio when to turn on and off. the yellow wire is the main power wire and is also responsible for keeping the clock and other settings after you turn the car off.

thanks alot for confirming that for me,     so far everything on the stock harness is exactly how its described in the color wire chart for the crx that i have been using as reference with, it has the color for each wire and description of wire for the crx stock harness, and to the right side of the chart, it shows the color wires that match the same ones, but that are on most newer stereo wire harnesses.

the color wires on the crx harness and the stereo harness adapter all match what the chart said exactly, so do you think it should be good enough if i just connect all of them together and then try to see if the head unit works or not ?       or is there something else i should do to really make sure before trying to turn it on ?,   to prevent damaging anything ?      

basically, so far i've connected a metra aftermarket stereo wiring harness to the harness off the pioneer head unit, matching the color wires to each other (the wires are labelled on one of them), and i used crimp cap connectors and a ratcheting crimping tool to connect them with, and i pulled on them hard to make sure all were tight and did'nt come out at all, then i connected the wires from a metra reverse wiring harness to the stock crx wire harness, and connected again with crimp cap connectors, and only ones i have left to connect are the 12volt battery memory wire and the 12volt ignition wire, and need to ground the ground wire to the chassis, and the head unit is mounted in the console but with the harness unplugged.

theres one thing i should figure out first before doing anything else, i noticed the dome light and dash clock did'nt work after working on connecting the wires to the stock harness ?, the light inside the ashtray still worked, but did'nt try the lighter, but i think they are all for the same fuse?,      anyway, i assume that the fuse for the dome light and clock blew?, i will look to check, but i wonder what would cause the fuse to blow? i had the negative battery cable disconnected while working on it, i made sure to cover all the wire ends and even put wire loom loosely around them so they did'nt touch anything when i went to connect the battery cable back on.    i remember i had a problem with the cigarette lighter not working or a fuse being blown for that, which i think is same one, and i finally fixed it after messing with it and putting a new universal lighter, i know the wiring for the lighter run right next to the wiring from the stock radio harness, so i wonder if something just touched one another?    i'll look at it more to find out more...

i found out that the fuse for the dome light and clock is also the same fuse for the 12volt constant wire from the stereo too,   

so thats probably why it blew ?,     maybe the end of the wire did touch something or something else?      i'll put another fuse in and see if it does it again ?

if theres a blown fuse then id just replace it after you have made all of your connections, if it blows again then id start looking for a problem.

to update,   i ended up figuring everything out, i used a multimeter to test and find out which wire was for ignition and constant on the stock harness, and i found where the wire for my antenna was, it was coiled up behind the fusebox, so i hooked it to the head unit, i grounded the black wire from the pioneer harness directly to a bare sanded metal spot on the chassis, and put electrical tape around the wire and wire loom to protect it, and i made sure all the wire connections were good and also put electrical tape and wire loom to protect as much of it as possible.

i hooked the battery up and the head unit came on and worked !!!, so i was happy i did it right, and plus the clock and dome light worked again, so it did'nt blow the fuse this time, maybe cause i moved and organized the wires better.

then i thought i should put a backstrap bracket to secure the back of the head unit so its held up evenly, cause it was sort of tilted.

i was messing with trying to make a backstrap that was the right length to reach to the hole on the frame i wanted to attach it to, but there were'nt many good places to screw it to on the back of the head unit, cause there were only a few small screws and if i used the screw, it was small enough where it would slip right through the hole on the backstrap, so i used a different screw with a wider head, and attached a bracket, but then after doing that, i realised i had a hard time trying to plug the pioneer harness into the unit, cause the backstrap was in the way, and cause i wrapped electrical tape and put wireloom that made the wire for the harness too thick to manoever around easily, and after messing with it for a while and trying to plug it in, i gave up, and had to take the backstrap off.

the next day i tried plugging the harness in again with the backstrap out of the way, but when i put my head behind the console with a flashlight and looked closer, i noticed some of the pins inside the hole the plug goes into on the head unit, were bent !!!,   probably happened when i was trying to plug the plug in just going by feel.

i could'nt figure out how to get the head unit or mounting sleeve out of the dash ?,   i was prying and pulling like crazy, and thats why i ended up doing everything from behind, when really i should of had it out and working on it where i could see the back up close, so thats why i ended up messing it up.

but i straightened the pins, one by one, with a small flat-head screwdriver, until i was able to plug the harness plug back in successfully, and i did'nt care about the backstrap anymore, then i had to bend and shape the edges around the front of the head unit and mounting sleeve so they were back to normal, so i was able to snap the front panel and trim ring up to it so they were lined up right, cause i ended up bending the edges around the sleeve and head unit when trying to pull it out of the dash.

i was able to get the front panel and trim ring on where the detachable face snapped into place, and attached battery back and turned the key to on, but it did'nt work !, and i was real disappointed and thought i just ruined it by messing with it too much, but later i looked at it closer, and noticed the bottom tabs on the front panel of the head unit (the panel the front face snaps over), were'nt snapped all the way into place, so i snapped the panel in around all the sides, then snapped the face on and connected the battery and turned the key on, and it worked luckily !

and later i found out to remove the head unit, i supposed to use the 2 extraction keys that came with the unit, sliding them into the side slots to pull it out, so now i know i should of tried that instead of trying to pull and force the head unit / sleeve out of the dash !    its still a little tilted since theres no backstrap, but its in good enough where its staying in place and where i can use it and press buttons without it moving, but later i will secure the back with a backstrap to lift the back up more and even it out so its level.

so, i messed with it, and set the settings, and it sounds good for what it is, and has good eq and loudness parameters to mess with.

but be better with an amp and a sub, which i will get later, cause thats what i had before my car was broken into, but this is good enough for now, just to be able to listen to music again.