Hi folks,

After being rather busy, I've gotten some time to play with my 740. I have a pdf that explains wiring up a new radio, but it's of limited help because I'm trying to diagnose an already installed aftermarket Pioneer CD player. It works well, but the rear speakers are silent, and adjusting the fader all to the rear will effectively mute the audio.

After taking off the panel underneath the steering wheel, I found several wires hanging (cut) and what appears to be one end of the radio harness (with connector intact) wrapped up and above the amplifier. This suggests to me that the harness has been seriously spliced, and the amplifier bypassed.

I cannot get my CD deck out, do I can't examine the spliced wires in there. Any suggestions, guys? I have one with the removable faceplate.

At the bottom of the left driver's footwell, peeking up along with the rest of the bundles of wiring, are what appear to be the cut ends for the rear speakers. The wires are what I would associate with a home stereo - amber, transparent, and carrying two separate physical wires per each 'wire.' There's also a third wire peeking up, and it only carries one physical wire (half the size of the other two wires). There's another amber 2-in-1 wire coming from the back of the radio (I think) that reaches all the way to the cut ends in the footwell.

There are also some other cut wires here and there. It's scary.

What is your advice, guys? The stereo works, just not the rear speakers. I'm leery of just starting to take things apart, or of randomly splicing things together. Any help would be welcome. To start, I know I need to get the CD deck out... so I'd welcome that advice first.

Thanks,

Ari

Hey Ari,


Good to see you back. Unfortunately, you're going to need to pull that radio out. You're going to need a wiring diagram with the sound systems' wiring. This guy has them: http://volvo.techno.org.pl/schematy.html. Use the schematics at the bottom of the page, they have the radio wiring. The ones toward the top are the 740 diagrams from the Haynes manual. The '87 schematic does not cover the US models with the amp, so you'll have use the earlier/later schematics. '86 and '88 are about the same, but in '88 they changed the wiring colors to the rear speakers. Using the wiring diagram, find the wiring that feeds the rear speakers. Most likely, this was botched at the amp harness or wasn't connected at the radio. What you are seeing may only be connected to the front speakers. You'll need to do some detective work to see what they did... You may need to add another pair of wires from the radio outputs to the cut amp harness under the dash. To get the Pioneer radio out of the dash, it has clips that are pushed in with a pair of 'keys' that fit into slots on the sides of the radio. You will need to remove the trim bezel to expose it. Its a pain to get the radio out without the 'keys'. I may have a set of those somewhere for an old Pioneer radio. I'll try to find them if you would like to borrow them. All they are is a strip of metal that pushes the spring clip out of the way and allows you to pull the chassis out of the metal sleeve that is affixed to the dash.


Regards, Jon

I emailed you using the BB email utility.

Thanks,

Ari