I just installed a new head unit and front speakers in my 325 this last week end. After doing it, I thought I would post up some tips / resources for other 325 noobs. I had looked through most of this car audio section, and I could not find any threads with basic details. Most were about doing bigger things than just replacing the existing components with better aftermarket equivalents.
My car still had the stock BMW head unit, I don't know much about it except that it was made in Japan. There is a good article at the following link:
www.pelicanparts.com/BMW/techarticles/E36-Radio/E36-Radio.htm
It says e36 in the link but the web site said that it was supposed to be for e30. The stock head unit removal was accurate but the wire colors were not correct for my car. The main point of interest is that it shows you where the hidden flaps that cover the screws that hold the head unit in. The head unit in my car had the same arrangement. I used a hex key in the internal pentagonal bolts and it did work. The bolt head appears to be soft brass and I don't think it will take much to strip it. In fact thought that I had stripped it, but it worked OK in the end. The bolts don't actually need to screw all the way out. They make appear to make a plate in each side of the head unit move out to lock behind the hole in the dash to keep the radio in. You just need to screw them in enough to get the head unit out through the hole in the dash.
On to the wiring. I guess you can buy adapters to wire the harness for the new radio into connectors that plug into the car wiring harness. I did not want to use the BMW fader switch, so I decided to run my own speaker wires. The stock deck that came in my car seemed to only have a left and right speaker output and then split at the fader switch (or after?). The number of wires running in and out of the fader switch did not seem to be enough wires for 4 speakers, but I did not have a wiring diagram. I only used the 12v constant, 12v switched, ground, and antennae wires from the existing harness. The Pelican article claims you need an adapter for the antennae wire, but mine was fine with out.
On the front speakers, they are 5.25" stock. There is very little clearance between the plastic kick panel and the speaker. You need to be careful that the speakers you buy have no tweeters mounted in the middle or if it does that it does not stick up out of the cone. A very small amount of protrusion might be OK, but you will want to measure first to be sure. None of the speakers available at any of the local electronics stores here have flush or recessed tweeters. You can of course modify the kick panel or make a new one to sort out clearance issues, but I am not interested in doing that.
To remove the drivers side speaker, first you need to remove the panel that goes under the dash. This is secured with four plastic fasteners, three at the top to the dash, and one farther down onto the steering column. The three at the top look like flat head screws. You need to turn the screw so that the drive slot is vertical. Then you should be able to stick something under the head and pop it off with out breaking the head off. The one at steering column just pops off, and then the panel should come off. You need to unclip the plastic box from the back side of the panel before totally removing the panel. The kick panel is fastened in four spots. There is a screw near the grill for the speaker, two bolts that also hold the hood release mechanism, and then the weather striping needs to be pulled back. Then the panel can be slid towards the front of the car and out. The speaker is then exposed. On the passengers side there is only the screw by the speaker grill and the weather striping. Once you get the kick panel off, it is easier to do the speaker with glove box off the limit straps. There is a plastic pin that pops out of the end of the two nylon straps.
I have not done the rear speakers, so I have nothing to say there. I hope this is helpful to some one.
Nic
My car still had the stock BMW head unit, I don't know much about it except that it was made in Japan. There is a good article at the following link:
www.pelicanparts.com/BMW/techarticles/E36-Radio/E36-Radio.htm
It says e36 in the link but the web site said that it was supposed to be for e30. The stock head unit removal was accurate but the wire colors were not correct for my car. The main point of interest is that it shows you where the hidden flaps that cover the screws that hold the head unit in. The head unit in my car had the same arrangement. I used a hex key in the internal pentagonal bolts and it did work. The bolt head appears to be soft brass and I don't think it will take much to strip it. In fact thought that I had stripped it, but it worked OK in the end. The bolts don't actually need to screw all the way out. They make appear to make a plate in each side of the head unit move out to lock behind the hole in the dash to keep the radio in. You just need to screw them in enough to get the head unit out through the hole in the dash.
On to the wiring. I guess you can buy adapters to wire the harness for the new radio into connectors that plug into the car wiring harness. I did not want to use the BMW fader switch, so I decided to run my own speaker wires. The stock deck that came in my car seemed to only have a left and right speaker output and then split at the fader switch (or after?). The number of wires running in and out of the fader switch did not seem to be enough wires for 4 speakers, but I did not have a wiring diagram. I only used the 12v constant, 12v switched, ground, and antennae wires from the existing harness. The Pelican article claims you need an adapter for the antennae wire, but mine was fine with out.
On the front speakers, they are 5.25" stock. There is very little clearance between the plastic kick panel and the speaker. You need to be careful that the speakers you buy have no tweeters mounted in the middle or if it does that it does not stick up out of the cone. A very small amount of protrusion might be OK, but you will want to measure first to be sure. None of the speakers available at any of the local electronics stores here have flush or recessed tweeters. You can of course modify the kick panel or make a new one to sort out clearance issues, but I am not interested in doing that.
To remove the drivers side speaker, first you need to remove the panel that goes under the dash. This is secured with four plastic fasteners, three at the top to the dash, and one farther down onto the steering column. The three at the top look like flat head screws. You need to turn the screw so that the drive slot is vertical. Then you should be able to stick something under the head and pop it off with out breaking the head off. The one at steering column just pops off, and then the panel should come off. You need to unclip the plastic box from the back side of the panel before totally removing the panel. The kick panel is fastened in four spots. There is a screw near the grill for the speaker, two bolts that also hold the hood release mechanism, and then the weather striping needs to be pulled back. Then the panel can be slid towards the front of the car and out. The speaker is then exposed. On the passengers side there is only the screw by the speaker grill and the weather striping. Once you get the kick panel off, it is easier to do the speaker with glove box off the limit straps. There is a plastic pin that pops out of the end of the two nylon straps.
I have not done the rear speakers, so I have nothing to say there. I hope this is helpful to some one.
Nic
Comment