Bose Speaker Amps/radio face

[LancePearson]

I'm wondering...do I have to have the radio head case metal side brackets screwed into the opening so that a negative comes from the reception of the screws to complete the light circuit? I just have it sitting there, not screwed in at all. I wonder. I'll call Dr. Don Monday and see what he says. The photo showing the cd track 1 playing appears orange but that's from the flash of the camera not the two bulbs of the radio. It might depend on the ground pickup through the fastening screws to be connected to negative power to trigger the light functions.

I'm too lazy to do any more experimenting at the moment but I do wonder.

[Fully Vetted]

Good time to put in a shift light if you don't already have one.

[LancePearson]

shift light inside the a/c vent would work. Not a bad thought.

[Schrade]

Originally Posted by LancePearson

I'm wondering...do I have to have the radio head case metal side brackets screwed into the opening so that a negative comes from the reception of the screws to complete the light circuit? I just have it sitting there, not screwed in at all. I wonder. I'll call Dr. Don Monday and see what he says. The photo showing the cd track 1 playing appears orange but that's from the flash of the camera not the two bulbs of the radio. It might depend on the ground pickup through the fastening screws to be connected to negative power to trigger the light functions.

I'm too lazy to do any more experimenting at the moment but I do wonder.

Schematic section 8A 151 does not show a ground integral with the Head Unit housing.

However, the more places that those unruly electrons can disperse to, the BETTER! Just like kids, when they get together in a tight spot, trouble abounds yUP!

[LancePearson]

Originally Posted by Schrade

Schematic section 8A 151 does not show a ground integral with the Head Unit housing.

However, the more places that those unruly electrons can disperse to, the BETTER! Just like kids, when they get together in a tight spot, trouble abounds yUP!

Shrade...does it show an in head fuse for the lights..I tried a contact from housing to screw holes...no change so that confirms what you said. All the green in head lights work function by function but the two incandescents dont...I suspect a fused circuit as the culprit. Darned radio works perfect with good sound otherwise and no face scratches from previous owner any more. I dont have the diagram.

[Schrade]

Originally Posted by LancePearson

Shrade...does it show an in head fuse for the lights..I tried a contact from housing to screw holes...no change so that confirms what you said. All the green in head lights work function by function but the two incandescents dont...I suspect a fused circuit as the culprit. Darned radio works perfect with good sound otherwise and no face scratches from previous owner any more. I dont have the diagram.

No lights? But the LCD DOES light up?

I didn't see a fuse while inside the HU; Bob carstereohelp.com is going to get to me a schematic for the unit itself Monday - talked to him Fri night.

Looks like the solid Grey might be the culprit. It's in the smaller of the 2 HU harness connectors.

HU troubleshoot chart 'No Incandescent Display' says, "Park Lamps on" ? Dimmer NOT at 'minimum'; then refers to Interior Lights T/S chart.





'Dimmer' troubleshoot chart 8A-117 does NOT show isolation for HU incandescent lights!!!

Bent pin?

[LancePearson]

I double checked the dimmer switch setting this morning. When parking lights are on all the orange back lights on the radio light just like the rest of the dash and are dimmed or not with the dimmer. When the radio is on and you push a function button the small green lights come on as they should. It appears the incandescents that light the radio in orange are the lights which make things orange through the distribution plastic and are controlled by the dimmer and they are both on and working. Hard to imagine I damaged both incand. Small bulbs since I touched neither and I now know they are working because they light a lot when you turn the parking or headlights on.

I now think what happened is that when I switched the existing circuit board from the back of the old scratched face unit then incorrectly tried to put that unit back on the radio while it was in place and did not get the pins right that in pressing somehow I must have damaged some type of very tiny, low current draw light wired directly into the inside of that board on the back of the face unit itself which illustrates the displace space alone for the clock, the radio station, the cd track, etc. info which is displayed either through pushing too hard or some other mechanism.

Every other light, of which there are many displays, on the radio and every other function now works perfectly save that. The display displays and in daylight it works well enough to use but when light is low the letters displayed in the display are black and need the contrast of a low level backlight.

I won't take it apart again since I am not up to soldering on a solid state board and if the used/new unit coming works I'll drop it in then send this one back to Dr. Don and let him do it and return it to me. I know it's not popular to say this here but I like the radio and the sound that comes out of it in the car and won't mind having a ready backup just in case. It's been a learning experience anyway.

I did not take a photo of the inside of the board on the face unit when I had it apart, only the completed and assembled face unit from the back so I can't be sure but logic gets me here and I now see for 99% that the two incandescent 1/4" diameter bulbs appear to be working perfectly. Therefore, it's probably what I think . Thks for diagram.

[LancePearson]

on the Corvette Forum Alchemist posted these instructions and there are bulbs on the board for the face and that must be what is shot on mine. I'll repost it here and have saved it and will look into either getting the bulbs and soldering or sending to Dr. Don and let him do it. I'm not confident in my soldering ability and it is only the display bulbs on mine that aren't working. I'm not surprised I did something as it was not done right the first time.

Here is some interesting info that Bose automotive just sent me...the head is made by Delco to feed the other parts..

"....Thank you for your inquiry. I am sorry to hear that you are having problems with the Bose Music System in your 1991 Chevrolet Corvette. The speakers/amplifiers are manufactured by Bose Corporation and the radio/cd portion of the system is manufactured by Delco Electronics...."


Ok Guys! You asked for it...you got it. Here's the text from the tech tip on replacing that lit'l PITA Delco bulb! I just wish i could remember who originally posted this to give credit where credit is due!

Steps for Removal Of the Delco-Bose Radio for light bulb replacement

Before doing anything, take a good look at your unit at night and determine where the dark areas are. This will help you understand which bulbs require replacement once you get the radio apart.

Parts Required
Radio Shack
12 volt, Bi-Pin, 50 milliamp bulbs - P/N 272-1154 ($1.39 each) 1 per package

Pulling the Head Unit
With car sitting on a level surface, apply emergency brake and select neutral with shifter.

Turn ignition switch to off.

Pry shifter button out of shift knob by inserting a thin blade screwdrivers on each side of button.

Use a pair of straight nose snap ring pliers to remove spring clip on shifter knob.

Pull shifter knob off of shift lever.

Remove shifter trim plate by first removing two 7 mm screws inside console.

Pull corners of carpet up to reveal screws.

Remove the one 7 mm screw that is found inside cup holder.

Gently lift up trim plate until you can unplug shift indicator light. Rotate light socket to disengage from plate.

Unplug cigarette lighter socket by prying the two tabs and slide socket off of lighter receptacle.

Leave rear deck release wiring attached to button, and swing trim plate to the passenger seat.

Lower steering wheel by tilting to the lowest position.

Remove two cross head screws in A/C duct, and remove grill

Remove radio trim plate by first removing two screws at bottom of plate and one at top right. Be careful when removing trim plate because there is a spring clip on left side. Pull straight out to disengage clip.

Radio has 4 screws that hold it into dash. Remove all 4 screws, being careful not to drop any. They are hard to find once you drop them.

Remove radio from dash, by sliding out and at the same time prying the trim away to allow room for the radio attachment ears. If you are not careful, you will scratch the trim work.

When radio is out sufficiently, unplug the two electrical connectors. Don’t worry; they are keyed so you can’t mix them up when plugging back in.

Repairing the Backlight
Take radio to workbench, or table, and lay a soft cloth or cardboard down to protect both the radio and counter top.

Remove the top cover of radio. There are about 13 small screws located on the top, back and sides. With top off, remove the volume, balance, and tone knobs by pulling off. These knobs are specific to each function, so don’t mix them up. If you do, no big deal, you just have to sort it out.

Next, you want to remove the faceplate. This is done by gently prying the tabs that are located on the top and sides. The face will rotate out at the top first. Continue rotating until you can disengage the tabs on the bottom side. Pull the plate out far enough to disconnect the two connectors on the ribbon cables going to the back of the faceplate. Once the cables are disconnected, the plate can be completely removed from the radio.

There are 4 small socket head screws on the circuit board that hold the circuit board to the faceplate. Lay the face plate face down and remove the four screws. Gently lift the board away from the face plate. Be careful and don’t accidentally dump out all your face plate push buttons, cause then you won’t know which button goes where…unless you have a better memory than me. My savior was a picture of the radio in the MidAm Catalog. Need I say more?

Now, where were we? You will see 3 lights around the display, and four lights in the pushbutton area. The 3 lights around the display are identical to the ones you bought at Radio Shack. Unsolder the old ones and replace. The 4 in the pushbutton area are not an exact match in size, but they work, and are easy to solder into the board.

When all lights are replaced in the board, set it aside and look at the two light bulbs by the volume and balance controls. The top light is replaceable, and can be removed by grasping with your fingers and pulling out. Replacement bulbs are available at AutoZone or at the dealer. Don’t ask the dealer to look the part up on his computer, cause he won’t show it. Just show him the bulb. The bottom light is hard soldered and if you must replace it, use one of the bulbs you purchased at Radio Shack. Again, the bulbs won’t be an exact match, but they work just fine.

Re-assembly is pretty straightforward. Be careful, and when re-installing into the dash, slide the unit in far enough to hook the two connectors up, then try the lights prior to final assembly.

Don’t forget to slide the shift indicator slot over the shifter tab when lowering the console plate back into position.

(Edit to correct spellings and make article more readable )

[LancePearson]

a diagram service sent me the system diagram schematics today so I'll pass it along. It does not go inside the boards but is a fairly clear presentation of the system as I see it.delco bose radio diagram schematic.jpg

[cvette98pacecar]

Originally Posted by LancePearson

I haven't pulled the radio head yet. I need to pull the center tunnel and shift tunnel and console trim first to check shift boots, add some sound proofing then change the radio face place so have not done that yet. I'll unplug the battery this weekend and start removing the trims to reveal and do the three things since they all share the same need.

From what I've seen of the back of the radio head there are a couple of wiring harness connections behind the head which might be able to be tapped for such a thing. Presumably power in then outputs to the CDM below the glove box and to speakers from that. I haven't looked at the wiring diagrams at all. If you can tap in for a 1/8" plug seems like you could mount it in the trim piece below the radio itself as wire length wouldn't matter a whole lot there.

In my case I don't think I have to pull the radio head at all just to put a new face on it as without the trim it's all exposed.

How do you do what you said with the added aux? I'll add a photo of someone elses radio back if that will help.


Lance

Lance Don't waste your time or money with sound proofing. I did dynopad and dynomat throughout the entire cockpit and it made no difference in reducing road noise.