1990 honda crx si, head unit

i'm installing my first head unit and wanted to make sure i'm covering everything, not leaving anything out? car is a 1990 Honda CRX Si, a couple years ago my car was broken into and they stole my head unit and my amps and they cut the factory stereo harness plug off. someone on the12volt forum pointed me towards the correct harnesses i needed for my car, so i got a metra 70-1720 harness adapter and a meta 71-1720 reverse wiring harness, and the new head unit i got is a Pioneer DEH-150MP. i don't have amps or subs, its just going to be a head unit and 4 6.5" coaxial speakers in the stock locations, so nothing complicated. i understand how to install the head unit, and am sure i can do it, but i just wanted to mainly cover some things before starting, just to make sure i understand everything correctly and am not forgetting anything ? first question is, since they cut my harness when stealing my last stereo, what things do i need to check that would be affected from that happening?, like any fuses blow? i should replace before starting install? or any other things to check ? do i need to put a ground wire from the back of head unit to the body of the car ?   on the new head unit i got? or not?     or is that only to get rid of ground noise problems? theres a blue wire with white stripe coming from the pioneer head units harness and its labelled "system remote control", but the blue wire on the harness adapter and reverse wiring harness i got are labelled "power antenna", is that the same thing?   or not?        also, theres an orange wire with a white stripe called "dimmer",   coming from the harness adapter but there is'nt an orange wire on the pioneer wiring harness? so where would that orange wire connect to? any help with these questions,   would be appreciated,      thanks

you will definitely want to check for any blown fuses and once you find which once are blown i would leave them out until you are finished wiring the harnesses together so that you dont risk blowing the fuse again. you will probably end up with some extra wires that exist on one harness but not on another. usually the power antenna wire can also be hooked up to the remote wire because radios these days are being build with just the remote output instead of both remote and antenna outputs. you might need to add a relay on the remote wire from the radio if you have more than one or two other wires hooked onto it. the new radio doesnt have a dimmer input so just cap off any orange wire in the factory harness so that it cant short out when you turn the lights on. you should be just fine if you want to use the factory ground wire but personally i like to run my own whenever i can just to avoid any possible issues, especially if im installing a multi-media or navigation radio. i screw my grounds straight to a part of the frame for the dash that has no paint or sand some paint off of the floor for a ground.

thanks for the info,     my head unit does have ability for you to adjust the brightness level of the head unit display illumination, would that feature not work if i did'nt connect that orange dimmer wire to anything ?        or do you think its nothing to do with that ? when you say i should be fine using stock ground wire,   do you mean just connect the black ground wires in the harnesses to each other, and thats all ?    i mean is that all i need to do really ?   does'nt it lead through the stock harness and the other end of the black wire is grounded somewhere ? or do you mean i would have to splice into the stock black ground wire ?      i just don't understand that part exactly ? and if i were to run my own ground wire, where would it connect on the head unit ?       thanks for your help

no if the head unit doesnt have an orange wire in its harness then theres nothing you can connect to. youll still be able to adjust the brightness, it just wont be automatic when you turn the lights on. if your harness has been chopped off already then i would run a new ground because just because a wire is black doesnt mean it is a ground wire. if you run your own then you know you are doing it right.

when you say i should run my own ground wire, do you mean connect the black ground wire thats coming from the pioneer wire harness and run it down connecting it to a metal part of of the chassis ? with a ring terminal at the end and self-tap screw ? as opposed to just connecting the black ground wire from the pioneer to the harness adapter, and to the stock harness . . . . ., depending on the stock ground at the end of the harness ?     if so, then do i just cap off the black ground wires coming off the harness adapter, reverse wire harness and the stock harness ?    thanks