Xm Splice (hardwire) Into Oem System Casette Deck

[BoaR]

Bit of help if you can guys. I was trolling through both forums for more info and managed to figure out what the hell im up against here.

Long story short I have a xm module, the antenna/power hardwire is easy to figure out. What I wanted to do is pop opened the center dash radio unit, use something like the out AUX RCA home kit wires they give you for the unit (its sort of a 2.5mm to red/white rca adapter) to snip the rca plugs off the end and hardwire splice them directly into the area that would normally feed the casette adapter.

In my head this would be working something like: XM radio -> output wire -> rca ends snipped -> fed to snipped casette wires (soldered together) IN the dash -> making the car think that the signal when you push the casette button is coming from the "casette" in the slot.

Think this would work ? or am i overlooking something totally obvious? If the deck wiring is a bit much you think I could find the pinout to the amp, and splice the out of the xm radio unit directly to the "imput" of the casette there?

All in all the goal would be keeping everything as OEM looking as possible, no aftermarket showing, and allowing the cd and xm to be used. hardwired obviously for best quality.

Thanks for a quick brainstorming, as I plan to start working on this saturday :)

[1990LS400]

I've seen several threads on Lexus forums on how to do this. Here is a recent one on ClubLexus http://www.clublexus.com/forums/lexus-audi...-aux-input.html but it is not the best method if seen ... I'll keep looking.

The "best" method I've seen cuts the cassette drive motors and does not require the use of a cassette tape.

[BoaR]

Thats pretty much exactly the style of thing I was looking for, thanks !

It gives me an idea of just how much trouble this will be to pull off. Should be fine :P

if you happen to land on anymore info anyone please post it up. :)

EDIT: hmmm reading everything over again makes me think...

If the setup is going something like |casette| -> |processing| -> |capacitors| -> |AMP|

then instead of inserting the 2 wires(*) inside the unit here:

|casette| -> |processing| -> |*capacitors*| -> |AMP|

then why not just run them directly to just before the amp, or insert them directly at the amp level here

|casette| -> |processing| -> |capacitors| -> |**AMP|

as it is pretty much the same thing... only thing would be to find out on the amp pinout which is the casette IN pin numbers and see if I can put it directly there.

what do you think ?

[1990LS400]

I'm not an electronics guy but why do you think there are separate pins on the amp for the cassette deck? Wouldn't all three media types (radio, CD, tape) share the same signal route from the head unit to the amp?

A potential problem with using the method described in the link I posted is that cassette decks can make quite a bit of noise. Mine clicks like crazy -- probably worn out. Unless the cassette drive motors are defeated when tapping into the cassette deck to add RCA's, one would have to put up with the cassette deck noise.

[BoaR]

Hmm I see what you mean thats true.. I guess I'll be hooking into the capasitors after all lol.

The casette drive doesnt make noise on mine.. maybe your's is just totally finished. (you play lots of mixed tapes? lol)

Thanks for the ideas guys, if anyone has more please post them up. :)

[1990LS400]

I just noticed a thread on ClubLexus about eBay seller "factoryradios" in California charging $60 including return shipping to add an aux-in jack either to the front of older Lexus radios or to the back of radios with a cable running around to the front. Here is the ClubLexus thread: http://www.clublexus.com/forums/lexus-audi...ereo-w-aux.html

Attached are photos from the eBay advertisement. I wonder if the guy could wire in a switch so that the aux cable wouldn't have to be unplugged to use the radio's FM.

Sounds interesting.

[BoaR]

Well, The project is nearing the end.

Long long road (if you are even thinking about attempting this - start early in the damn morning, because you WILL finish very late at night).

I need to tweak the system a bit to get rid of a hum (I'm thinking its a ground loop fault.) but in general everything is working.

Few tips if you are planning to start this.

-> Yes it works, and is possible, you just need a nice day (garage) and lots of time.

-> multimeter (voltmeter) life saver. beg borrow or steal one. you WILL need this.

-> HOT soldering iron with very fine tip. dont think of using a *BLEEP*ty one that cant get hot enough. 400deg+ is required for clean precise soldering. If you screw up in the radio you just blew everything. the board circuitry is tiny and needs you to pay great attention. some fine nose pliers might help you out too if you have chubby fingers. watch that you dont blob on the solder and accidently jump the circuit paths. Also I put some tape over and around the connections (thin strips) to make sure they dont touch anything. BE GENTLE.

-> Big blocks of wood to jam and lock the wheels. depending on your year of car, the key might need to be Acc/ON to move the shifter into neutral etc. very dangerous as the car can/will roll. block lock the wheels and feel a bit safer. mine is a '95 and it required the key turned to move the shifter.

-> good lighting. annoying as hell reaching around in the guys of the stereo hole. (I used a hang garage light, opened the moonroof and hung it up there.)

-> PRINT the link above. for the SC radio capacitor thread. don't be an idiot like me down in a garage needing to google up the thread on a cell phone.

-> PRINT a googled stereo jack wiring/diagram. how to wire in the ground etc.. or at least read all about it before.

-> PRINT a googled radio console removal for your year of car. there is 1 site that always comes up in google that is good.

-> get multi guages of wire. I prefer solid core, but stranded is fine. you need a heaver guage to extend your cig lighter socket. and smaller guage to do the stereo jack plug.

-> get spare 15A CAR fuses in advance. (3-4 minimum). I blew 2 in testing the 12v circuit. end of wires touched because I was not carefull and insta-blew the fuse under the steering wheel. It's the radio blue fuse that goes.

-> Get spare 2A 250v glass tube fuses (come in packs of 3 in the hardware department of canadian tire and cost $1.50). These are for the stupid cig adapter that comes with the XM radio. (the one that will convert 12v to 5v for the unit. The fuse is a piece of *BLEEP*, replace it right away. unscrew the end, flathead to muscle the 2 halves apart, and you can see where to pop the fuse. DONT LOSE THE SPRING when unscrewing it. My fuse in the adapter blew instantly, and caused me an hour of searching why the hell nothing was working. save the headache, pop and replace yours right away.

-> When splicing into the capacitors in that other thread. guy mentions blue dots. on my unit there were NO dots. they are soldered like <faceplate> |pin| <back of unit> hard to describe, when you open it you will see instantly follow his images. use the pin facing the rear of the radio. leave the one near the front UNtouched. and yes you need the capacitors dont rip them out.

-> dollerama VELCRO sticky backing circles, strips. this will save you TONS of time with the antenna, wire hiding etc. Get some electrical tape while you are there and some small zip ties. grab a garbage cassette adapter to destroy while you are here.

Overall that is the heads up so you dont have to go running out halfway through cuz something broke. The most annoying problem I had was the 12V rewiring electrical problems. After doing your extention, I strongly suggest testing to make sure you have 12v coming out. (on my adapter it was the blue/white wires supplying the power out. but TEST your's first before snipping etc.. its hell on earth to snip, trim, solder, getting my cig lighter moved to under the cubby to hide all the connectors and wires, especially after you do it all you find out the 12v isnt even getting to your new outlet. the antenna was velcro'd to the 3rd brake light INSIDE the car. our windows are so angled back that its far out. glass doesnt affect it, seems perfect as it is.

You need to place a gutted casette in the player, hit tape and then your stereo wired in plug is activated. (else you will play double sound). I need to still solve the hum ground problem (im almost positive its that) and will post up more details once that is done.

project was a big one, but im happy its nearly done and is working "in general". as with anything needs some tweaking but hey - thats what long weekends are for eh? ;)

[BoaR]

Phew !

Got it :D

Thats what it was in the end. Ground loop fault, meaning that you would get a loud incredibly annoying hum/buzz soon as you connect the stereo jack output to the unit. The solution was to get a ground loop isolator. a sort of little box that goes =|box|= and the two lines coming out are RCA jacks.

you just plug everything together like --xm output wire--> =|ground loop protection box|= --> modified stereo (the capacitors etc..)

That being said, if I ever have to do this again I will save about 40 bucks in extentions and connectors (chalk it up to the cost of future knowledge this time), instead of soldering a 1.8mm stereo jack as the other end of the capacitor modified wires (originally it goes capacitors -> stereo jack plug) I would just take the wires and do 1 wire left & right (like normal) directly into each their own FEMALE RCA plugs.

why female? the ground loop isolator has male male pins out both ends. so it would be super easy to just plug in after eliminating 2 extra connectors. Also your system will need this part anyways even if you want to swap out the xm to ipod etc..

But it's always 2 steps forward in hindsight eh? haha

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So if you want to do this project, follow the steps above. Also I strongly suggest just doing the capacitor mod with female rca plugs at the end instead of the stereo jack. as the output is 2 male rca's that you can just Y back with a 5 buck extention into a stereo jack to play anything. (xm, ipod, mp3 etc)

Hope this helps everyone.

Thanks Jim for the links that made this possible !

B)