OK, so before I start, let me say that everything I have worked on so far on the truck electrical, has been a hack job...

The problem I am having is speakers cutting in and out. The speakers on the passenger side come and go. At first I thought they were blown, but they do come on from time to time...The speaker in the rear door does not work, ever. The speaker in the drivers door and driver side dash always work.

I pulled the head unit (Pioneer DEH-P4500MP) and all the connections on the harness are good solid connections (that's a first for this truck, something wired correctly)
I have yet to tear into the doors to see how the connection is on the speakers.

A guy I recently bought some parts off of said he had a car that had been doing the exact same thing, the problem ended up being an OEM amp (similar to those found in the Bose and Monsoon systems). Did the blazers ever have these amps? If so what RPO code would I be looking for?

Finally... when the time comes for me to open up the doors, I do have a set of 6.5" speakers in storage. How much of a pain are they to fit in?

I'm a bit of an audio noob, so, sorry if these are dumb questions...

 

I've personally not ran into one of these trucks with an OEM amp. That sure doesn't mean certain models had them, just none I've run into yet and I've not been in one with a Bose/Monsoon system either. IMHO I highly doubt that any of them would have an OEM amp without the Bose/Monsoon systems, but I've been wrong MANY times in my life so take it for what it is, my limited experience with these trucks.

Also, how is the HU connected to the truck harness? Did they hack the factory plug out or use a harness adapter? If they hacked the factory plug out then you should really check all the wires and be sure it's connected correctly. If they got something wrong then it's not impossible that the internal amp of the HU may be damaged. If they used a harness adapter it still wouldn't hurt to verify everything. Also be sure to check all the wires and the pins they connect to. It's only happened twice, but I've had two Shosche harness adapters that had a couple of wires that weren't crimped into the pin in the connector properly.

Also, just because the speaker sounds okay when it works doesn't mean it's not still bad. The most common problem with these factory speakers seems to be the tinsel leads. The connection to the voice coil wires fails a lot which is what causes the intermittent operation or altogether not working. Changing them isn't much of any big deal though. Almost all aftermarket speaker mounting holes will not line up with the factory ones. It's not a big deal you can just put the screws through the plastic a little to the side of the factory ones. Otherwise there shouldn't be much of an issue.

 

They used a proper harness adapter. I will verify that the wires go to where they are supposed to go next time I have the dash apart.

My main worry with the 6.5" speakers is the physical fit. I had a Grand Prix before, which is where I intended to put these, but I never got around to it because I would of had to make my own adapters, it wasn't worth it in the end...

 

That's good they used the harness adapter. I haven't found what year your truck is yet but on my '01 Jimmy SLE I was able to easily mount the 6.5" woofers from my Phoenix Gold RSD component set in the factory plastic mounts. They've got a pretty decent sized motor on them and are fairly deep and the motor is a gnat's *** from touching the window track but they fit. So unless your speakers have larger motors or are a fair bit deeper in mounting depth I don't see where you'll have any issue.

Also it may be some work and trouble to build your own baffles to mount speakers into, however it's generally worth it every time. The more solid the structure is that any speaker is mounted to the better it plays. Bass is generally more robust and defined and midrange is often times clearer and better defined as well. You see when a signal goes through the voice coil and it goes to push the cone the motor structure is pushed in the opposite direction. The cone is many times lighter and has considerably less mass than the frame and motor does so it moves easier but as Newton's law states "For every action there's an opposite and equal reaction." When the speaker is mounted to a flimsy structure it loses some of the force that would normally be transmitted to the cone into the structure. Hence the more solid the structure it's mounted to, the more of that force is transmitted into the cone and the better it works.

 

Thanks, that's reassuring. I can't remember the specs on the speakers I have. I should pull them out and try to track down 2 more though...

My Jimmy, is a 99 SLE. I just haven't taken the time to make a sig just yet.