I am replacing the factory stereo with a new pioneer head. The problem I am having is which wiring harness I need for the stereo to work. The guys at the store told me I needed the GMRC-04 in order for it to work. The problem is its $100 itself. I found a scosche wiring harness that fits my Bonneville as well for much cheaper. I was wonder, will the cheap on work with all of the steering wheel controls? And also will it work with the delayed shut off after the key is taken out (and doors remain closed)? Will it work just as well as the expensive one? Or will it not function properly?
Well I'm not an expert on your car, but since it's just a harness, yeah, it should all work. All those functions you mentioned come from relays, little if this does this, then this will do this switches. i.e. if you press a button on the wheel, the volume will go up. Now, I'm not sure that your head unit will necessarily support that, but usually decent HUs (like pioneer) will have that. Bottom line, assuming that there aren't any loose wires because of it (and there won't be,) the scosche will work just as well as the GMRC-04. The only problem you may experience will be the head unit's fault. Bottom line, they're the same. Only thing I'd be hesitant about is the steering wheel stuff though, not all head units will support that. Delayed shut off will work for sure though.
Here's what's going on: Your head unit is controlled through the vehicle's data bus system. The GMRC-04 communicates with the vehicle data bus to keep the radio-controlled functions working; it also reads the radio on/off signals and uses them to control an accessory power circuit for the after-market head unit. If you use the GMRC-04, the after-market radio will work with the retained accessory power feature, and the vehicle's warning chimes (which are controlled by the factory radio) will still work. Now the question is, what Scosche harness do you have? If it doesn't include a separate control box, then it won't work like the GMRC-04. Scosche does make a harness, the GM07B, that fits the factory connector strip, and it will give you the speaker and constant power connections. However, it won't give you retained accessory power, and it won't keep your warning chimes working. To make the after-market radio work at all using the GM07B, you'll need to find a switched power source somewhere else in the vehicle--there's not one in the factory radio connector. Scosche also makes an adapter that's their version of the GMRC-04. Scosche's model number is DCGM14B. If you have this adapter, it should work similarly to the GMRC-04; but it's not a cheap adapter, so I'm guessing what you have is a GM07B. By the way, NONE of these adapters will keep your steering wheel controls working. You need a completely different adapter, the SWI-PS, for this function.
you just have to make sure that the harness is similar to the gmrc-04if it comes with the module box that the expensive harness does then you should be finebut as for the steering wheel controls, if you replace the radio with anything youre gonna lose em. BUT, you are able to retain them but you gotta drop 100 bucks on a steering wheel interface control module, you'll have to wire it plus program it to work, sort of a hassle, but can be done. plus every pioneer comes with a remote so you really wouldnt have to worry about your steering wheel controls, just use the remote
