1989 Aux Inputs

[Tom_]

I just got my first Reatta two weeks ago and I love it. Everything worked after a few hours of replacing light bulbs, fuses and the photocell in the dash. The questions I have are related to the stereo. My stock unit works and the speakers have been replaced in the rear but I have a fairly nice system laying around from another project that doesn't have a body yet. I know my way around a stereo install pretty well but I'd like to know a few things. The tape player in my car has been replaced with an Alpine GPS unit and I don't have access to a tape deck at the moment and I want to run AUX inputs for my phone. This is directed mostly at padgett from something I unearthed on a few threads where he said to assert the #13 pin which is the "T-ON" wire. I know this is the tape detect wire. What does he mean when he says assert? If that wire just needs a 12V signal to trick the radio into thinking it has a tape then couldn't I just splice into the yellow wire on the top of the radio that's only hot when the ignition is on? Also could that wire be used as the remote wire for the amp I'm putting in the trunk? I definitely want to keep the touch screen and radio interface stock looking even though I have a head unit, just with an added sub, amp and 6x9's in the rear.

[padgett]

Said "assert" because I do not know if it wants ground, 5v,12v, or "something else" e.g. 12v through 20k ohms. Anyone know ? Wouldn't want to fry a radio with the wrong connection.

[Guest Mc_Reatta]

There's a lot in your post that needs more information to give best response.

Is the Alpine GPS wired into the radio now to give audio directions thru car speakers?

Do you want to continue with your stock radio or replace it with your alternate head unit?

D.A.N.I.E.L did a great write-up of keeping CRT controls while using an aftermarket head unit. But most of us use the stock radio and hook up an aux input lead to play an m3p player etc. thru it.

The CRT can then switch from radio to aux by using the tape deck screen's play button. Switching is done in software vs having to put 12v on pin 13 (tape-on).

Aux amplifier is usually switched on via the pink auto power antenna wire.

When you say hook up your phone, do you just want voice (mono) input, or stereo capability for music. Stock radio has a dedicated cell phone input for mono.

There is also the option to install a blue tooth receiver to get input from phone, but not that great for music fidelity vs hardwire.

[Tom_]

Phone means mp3 player. Sorry for the confusion. The GPS plays through an internal speaker. A CD changer in the trunk is, I believe, wired to play through the speakers via tape deck inputs but since the battery has been replaced after the tape deck was removed, there was no way to make the tape detect active again so the P.O. just stopped using it. I'd like to be able to do something simple with the detect wire. If somebody had one hooked up and could be bothered to test what kind of voltage is running through it that'd answer the question. I had also thought about the pink wire for the radio antenna as a remote wire but wasn't sure if I should use it or not.

[Guest Mc_Reatta]

!2 volts applied to tape on (pin 13) input will do the trick then to switch the radio to aux input mode.

Same as CRT-less 90 owners have to do to switch their radios into CD mode to use an aux input.

Could pick up a used cassette deck that has bad drive belts for next to nothing, Then just need to load any cassette (even one with no tape inside) into it and plug it into the harness and switch to radio on, tape mode, play. Once the BCM sees the player it will remember it even after it is removed, until BCM loses power. Then just repeat process again.

[wws944]

!2 volts applied to tape on (pin 13) input will do the trick then to switch the radio to aux input mode.

Same as CRT-less 90 owners have to do to switch their radios into CD mode to use an aux input...

For clarification: On a '90-'91 integrated radio, the pin 13 that you are referring to is on the 16-pin plug which mates the receiver box to the rest of the unit. It is NOT the big 20 pin (actually two 4-pin and two 6-pin) connector on the back of the receiver box. Thus pin 13 is somewhat inaccessible. However these units have another connector on back, C1 in the '90 FSM, that is located below the receiver box. I am pretty sure that applying a constant 12v on pin 5 switches the audio to AUX in (pins 11-14 on the big 20 pin connector).