JBL Premium Sound Problems

MSwen22780

Registered User
I am looking for some possible asnwers why I am experiencing problems with my stereo. My '89 SC has the factory JBL Premium Sound with slave unit cd player. My radio works only in the morning but the right front and right rear speaker have like no bass and they are both extremely quiet. Later in the day when I try to play my stereo nothing works, even the power ant. does not move. If I turn my headlights on the unit will light up. I have not modified the system at all except for putting a new speaker in the subwoofer enclosure. I even tried using another headunit, but the problem still persists. I am wondering if there is a relay built inside the amp that powers the system. If anyone can help to figure out where to start looking for possible problems, I would greatly appreciate it!!!!!! I would like to keep the stereo stock or if I have to I will put in aftermarket equipment.
 
I'm sure you have heard that these systems suck !!!! They were made for ford by sony, they really are junk.

Here is what I did to test mine. I have an amp adapter that you can buy for splicing in a aftermarket radio to the JBL amps, I plug that in spliced the amp inputs into a old pair of head phones, and plugged that into a portable cd player, then reinstall you head unit, don't plug in the grey input wire to your amps, turn everything on, plug you home made test lead thing into the afore mention amp input wire, and you should hear music, that means that the amps and everything is ok.

You are probably going to find out that the CD player or radio is bad. Probably the cd player, the radio sends it's output through the cd player so when it goes you've got nothing.

The make a grounding plug that you can get that plugs into the radio and bypass the cd player, don't know where you can get one though,
If you can't find one locally, let me know I have one you can borrow, I also have that home made test harness thing too if you need it.

If it turns out the be a bad cd player or radio let me know, I know a guy on here who fixed my cd player, and it works great I'll get you his email addy if you need it.

Good luck
Tim

BTW as much as these system suck, I have the stock radio and slave cd player in mine, and I can't say I blame you for wanting to keep it oem. So far mine sounds really good too.
 
Thanks for the reply!!!! I will try this. I have a complete wirig diagram for the JBL system and I am slowing figuring what each wire on the radio does. I wasn't having any problems with my stereo last fall when I parked the car. I have already replaced the cd player about a year and a half a ago with a used one. Should the system still operate if I disconnect the harness off the radio for the cd player. The system acts like it gets hot and then shuts off. Is there maybe a relay somewhere that has to turn on the system like inside the amp or radio itself? The system still does nothing even if I swap headunits. I don't understand why it only works in the morning.

Mike
 
Sounds like your cd player has died. There isn't any relay or anything per say. What happens is there are capcitors inside the cd player that break down and leak onto the main board. Did you park your car outside? Heat is a big thing that will break down a good cd player. The radio will not play if you disconnect the cd player from it, you will need the grounding pin. I'll get you a picture of it, so you'll know what I'm taking about.

BTW I've never seen you around here before you welcome to the board, everyone here is pretty cool, so if you need anything just ask.

Let me know what you find.

Tim Atkinson
 
New info learned

When I got to work this morning I just thought I would try and disconnect the cd player to see if the radio would work and it does. It still acts the same in the afternoon and doesn't work. I am going to monkey with the amp in the back to see if this might be the problem. I just purchased a different amp on ebay cheap, so I am going to put it in when I get it. I will post the results when I receive the amp and install it.
 
??? When you swap out the head units, are you connecting the cd player? Try using a grounding pin (I have an extra one if you want it) that will rule out the radio or the cd player.

The amp is a good idea---- but one would think that both ams failing at the same time would be highly unlikely. Unless a rodent chewed through the grey audio cable (also highly unlikely) but you never know.

Let me know what is going on

Tim

BTW I struggled with the same problems with my radio when I got my car.
 
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