88-89 Prix 3-Piece AM/FM/Cassette/EQ Info

[Penglii]

Got fed up with the guess and check method of figuring out the ideal way to add Aux In to an 88-89 Prix 3-Piece Cassette w/EQ setup.

Now I am prepared to know way too much about this particular setup. I will post schematics and stuff here as I get around to it.

Behold!

[Penglii]

First thing I notice... On the cover of the Amplifiers book it says "Pontiac N -- 16124212", that is also the part number of the Pontiac W amplifier... I assume it's the same amp. Have not removed mine from the car yet to double check.

 

GM's parts numbering scheme gives me such a headache sometimes. LOL

[Penglii]

For starters, here is the overal diagram from the Factory Service Manual.

 

[ManicMechanic]

Got fed up with the guess and check method of figuring out the ideal way to add Aux In to an 88-89 Prix 3-Piece Cassette w/EQ setup.

Now I am prepared to know way too much about this particular setup. I will post schematics and stuff here as I get around to it.

Behold!

 

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

 

I am anticipating this...And where in God's good name did you get those??!?

[Penglii]

I got them from www.elliottsradio.com

Spent too much money on them, but I don't care, it's totally worth it to have this info.

Finding out what document numbers I needed to find in the first place, that was the hard part.

[Penglii]

Here is the diagram and schematic for the 16124212 amp that powers the door speakers and is located sort of behind the DIC.

It appears to be a single board affair.

 

 

 

Edited September 12, 2012 by Penglii

[Penglii]

Here is all the info about the Radio Head Unit 16075882 AM/FM/CLOCK/EQ

 

 

 

 

 

 

 

[RobertISaar]

holy hell, factory level documentation...

[Penglii]

And finally... the Cassette/EQ Module 16050912

 

 

 

 

 

[Penglii]

Some of those schematics are sort of hard to see the small numbers. Stay tuned and I'll re-image those at some point.

 

Unfortunately the Panasonic Cassette Deck 61483P the 88-89 GPs got is considered non-serviceable, that is annoying. Certainly explains why it was so hard to disassemble!

The cassette deck book has a bunch of actually serviceable units listed, I posted the cover page with the list. If anyone is interested in any of those specifically let me know and I will image those pages.

[ManicMechanic]

Post anything you can if you would...please. :thumbsup:

[Penglii]

Ten-Four

I will see what I can do about making pdf's of each book.

Stay tuned.

[Penglii]

OK... turns out that the amp I posted above is actually the amp for the door speakers. That explains why it's so simple.

Here is a pdf of Reciever 16072780 that is located behind the glove box.

http://webpages.charter.net/nahles/TGP/Delco_1990_TGP_Tuner.pdf

 

Edit: Just to add to the fun - I have paper copies of the schematics for the Reciever (that I just posted the pdf of) as well as the SWRC controls coming in the mail eventually. Then I believe I will have a complete set of documentation for the 88-89 3 piece unit. *grin*

Edited September 12, 2012 by Penglii

[Penglii]

Here is an old thread I found from 2005 with more (mostly redundant) info about this radio system. It's got a few really nice nuggets of knowledge though. Someone in this thread did some really nice hand drawn diagrams of how all the components link together. WAY more thorough than the diagrams in the FSM.

 

http://www.w-body.com/showthread.php/14875-More-on-the-89-radio

[RobertISaar]

WAY more thorough than the diagrams in the FSM

 

which is SO sad. GM gave the external connection diagrams for every other radio setup except for the 3-piece units.

[Penglii]

Yeah GM really dropped the ball when documenting this multi-piece setup, the diagram in the FSM is almost entirely worthless.

Even the factory-level schematics I have don't include any sort of halfway decent overall diagram of how all the pieces connect and interact. Hell, even the harness pinout diagrams those schematics include aren't particularly well labeled as far as which module they ultimately connect to.

[ManicMechanic]

Okay, here's how I did it to my van. And I just stuck a pen in the cassette to trip the mechanism, you'll probably just have to run a blank cassette.

 

I got a regular 1/8th stereo jack from Radio shack and some 22AWG shielded 4 conductor security wire.

 

Taking the wiring going to the external amp, in the 15 pin connector you will want pins 8 and 9. I believe they are brown/white and dark green/white looking at the thread in the link you posted. Circuits 367 and 368.

 

 

Here's the phono jack diagram.

 

 

I grounded the shield wire to a screw in the amp box.

 

Then I clipped and stripped the brown/white wire at the clipped ends, Then on the amp side I soldered the RED wire from the jack to this wire don't forget the shrink wrap, on the cassette side, I soldered the GREEN wire to this side.

 

On the green/wire wire, I clipped and stripped that. On the amp side I soldered the BLACK wire from the jack and on the cassette side I soldered the WHITE wire.

 

Works perfectly, once in while the tape mechanism starts going nuts since there's no tape in, but you won't have that problem.

 

Hopefully this makes sense.

Edited September 14, 2012 by ManicMechanic

[Penglii]

Cool.

That's actually exactly what I did, except I tapped into those same wires internally to the EQ unit instead of externally like you describe.

I found that I got diminished sound quality from that connection point, but I will find out soon if that improves with a non-failing amp.

 

Where I ran into trouble was when I attempted to bypass the cassette mechanism and implement a switch for that job.

I think that my trouble there was not using the correct wires.

Maybe it's a bit OCD of me, but I'd really rather bypass the cassette mechanicals completely for this.

 

I may abandon that approach entirely though... I may tap directly into the radio circuit of the amp this time and make a wire harness using molex connectors so I can run a length of wire through the existing harness ducting into the area behind the glovebox. That would allow me to have the jack mounted in the cassette/eq unit, have a simple plug and go interface, and allow me to remove either component (if ever required) without a big hassle.

[ManicMechanic]

If all else fails, this is an option...

 

http://factoryradioservice.com/chevrolet-radio-with-aux-input-p-97.html

 

$65+ 15 shipping to have someone do it for you without hassle. The 1988-94 Chevy trucks with EQ use the same amp as I sent you, although the Buicks have a better sound. The amp I sent is from a Buick.

[ManicMechanic]

Still waiting when you get a chance to scan those manuals...:thumbsup:

[Penglii]

Don't worry, I have not forgotten about that.... all good things come to those who wait. :biggrin:

[ManicMechanic]

Patience is a virtue...But it ain't one of mine. :lol::lol::lol::lol:

[DavidHowell3633]

Strange how we get this aux thing at the same time. I thought i had become obsessed but i see you are far ahead of me. I will be watching your progress with interest. Good luck and thanks for taking this on. I wired mine according to a post titled "DIY Delco UM6 and UX1 Aux input". But, i have no volume control using the radio or Swrc. Also, my clock display does not change until i remove the cassette blank.

Patience is a virtue...But it ain't one of mine. :lol::lol::lol::lol:

[Penglii]

Post #17 in this thread is a great description of how to wire in the jack portion of the mod.

 

To avoid the use of a blank cassette tape, I wired in a wired a switch to have the T-On circuit broken when off (Radio On) and have T-On connected and provided with +12v Power when on. (Tape/Aux On).

 

The reason for having to actually clip the T-on wire is because this method seems to bypass some relay that is used to turn the radio on/off when a cassette is removed/inserted. If you leave the T-on wire connected after giving it power then the radio will not come back on until you clip the wire... or I possibly until you insert and then remove a cassette tape to force the relay to cycle (It occurs to me that I never actually tried this).

 

The only problem I can think of is that the switch is now required to be flipped before a cassette tape can be played, because the internal relay has been bypassed, but that's fine by me.

 

I will draw up a simple diagram of all this at some point soon, maybe this weekend.

Edited October 3, 2012 by Penglii

[RobertISaar]

Damnit, the website is down.... may have to pick up the manual for the 90-93 GP CD unit.