HOT TOPIC: Key Sense Wire
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HOT TOPIC: Key Sense Wire
heres a good one that puts a smile on my face.
I had a devil of a time finding our key sense wire. I still dont remmeber if its accessible from the main distribution above the internal fuse box. maybe someone can trace it.
anyways, theres a harness right where our ignition jack is. if you drop the three screws in the plastic housing of the steering column, pop off the small top plate and remove both plastic pieces, youll expose your ignition switch. there will be two harnesses there, about five wires each.
I unfortunately cannot recall what wirecolor it was, but grab your handy dandy multimeter. itll read 12 volts with the key out, and as soon as you put the key in, itll drop to ground.
so all you have to do, is wire up a relay. put 12 volts constant on the coil and the switch pole. then wire that key sense wire to the other side of the coil. Finally, route the "normally open" switch throw of the relay to ACC on the radio.
Now, your radio turns on when the key is in the ignition, regardless of position. that includes cranking the car. Don't you hate it when your radio power cycles becase you turned the engine over? I sure did! Now it's fixed.
Enjoy!
I had a devil of a time finding our key sense wire. I still dont remmeber if its accessible from the main distribution above the internal fuse box. maybe someone can trace it.
anyways, theres a harness right where our ignition jack is. if you drop the three screws in the plastic housing of the steering column, pop off the small top plate and remove both plastic pieces, youll expose your ignition switch. there will be two harnesses there, about five wires each.
I unfortunately cannot recall what wirecolor it was, but grab your handy dandy multimeter. itll read 12 volts with the key out, and as soon as you put the key in, itll drop to ground.
so all you have to do, is wire up a relay. put 12 volts constant on the coil and the switch pole. then wire that key sense wire to the other side of the coil. Finally, route the "normally open" switch throw of the relay to ACC on the radio.
Now, your radio turns on when the key is in the ignition, regardless of position. that includes cranking the car. Don't you hate it when your radio power cycles becase you turned the engine over? I sure did! Now it's fixed.
Enjoy!
plus i have to much body work to do. 
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Rep Power: 337 the only thing missing is the exact wire color, which I can not remember. it will take someone about 3 minutes to find with a multimeter.
when I get back in about four hours, I'll post up the next relay wire job which really seals the deal and makes this effort worth while.
feel free to guess =D
when I get back in about four hours, I'll post up the next relay wire job which really seals the deal and makes this effort worth while.
feel free to guess =D
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Rep Power: 337 http://the12volt.com/relays/page5.asp#mtc
So, you can use the schematic to make your own latching relay. Hook up a - pulse (such as a key sense input
) and your radio will stay CONSTANTLY on. forever. Till 12 volt relay input power is removed.
why is this useful? well, if you hook up the "12 volt" line to the normally CLOSED section of a third relay, with a real constant 12 volts to the pole, you now have a way you can take any signal and interrupt your 12 volt line to the latching relay!
I chose to wire constant 12 to one half of the coil, and the negative half to my door pinswitch.
now, if the door is OPEN, (such as me sitting in my driveway or something) the radio turns off and on with key sense. done. key in, the radio is on. period. key is out, the radio is out. period.
with the door closed, the second the key hits the sensor, the radio is on, and stays on. even if you pull the key out.
till you open the door can you say nearly perfect functionality like radio's in GM cars? I can
So, you can use the schematic to make your own latching relay. Hook up a - pulse (such as a key sense input
) and your radio will stay CONSTANTLY on. forever. Till 12 volt relay input power is removed.why is this useful? well, if you hook up the "12 volt" line to the normally CLOSED section of a third relay, with a real constant 12 volts to the pole, you now have a way you can take any signal and interrupt your 12 volt line to the latching relay!
I chose to wire constant 12 to one half of the coil, and the negative half to my door pinswitch.
now, if the door is OPEN, (such as me sitting in my driveway or something) the radio turns off and on with key sense. done. key in, the radio is on. period. key is out, the radio is out. period.
with the door closed, the second the key hits the sensor, the radio is on, and stays on. even if you pull the key out.
till you open the door
can you say nearly perfect functionality like radio's in GM cars? I can 
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Originally Posted by MegaHurtz
Who wants to write a DIY (detailed, with pictures)? I'll give 50,000 points
Last edited by Scott Civic; Mar 3, 2006 at 07:17 AM.
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Rep Power: 786 I dunno where I'm gonna find the room behind my dash for all these relays 
, running short of room back there.
On the first relay, that would be a diode between pins 85 + 86, correct?
This 12v line being the "constant 12v(+) input" from the first two relays?
, running short of room back there.On the first relay, that would be a diode between pins 85 + 86, correct?
...if you hook up the "12 volt" line to the normally CLOSED section of a third relay, with a real constant 12 volts to the pole...
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Rep Power: 337 I used no diodes.
and yes, you are right about how to hook up the 12 volt lines. Looking at the schematic of the latching relay, we see a "switch" relay, and a "latch" relay. you can see that once the "latch" relay is toggled, itll stay on forever as long as 12 volts is applied! but as soon as 12 volts is disconnected, the latch relays stays off, even if 12 volts is reapplied!
so yeah, thats why we hook that up to relay #3 (door switch relay). lets us temporarily remove 12 volts form the circuit, preventing the latch relay from activating till we trip the key sense wire again
and yes, you are right about how to hook up the 12 volt lines. Looking at the schematic of the latching relay, we see a "switch" relay, and a "latch" relay. you can see that once the "latch" relay is toggled, itll stay on forever as long as 12 volts is applied! but as soon as 12 volts is disconnected, the latch relays stays off, even if 12 volts is reapplied!
so yeah, thats why we hook that up to relay #3 (door switch relay). lets us temporarily remove 12 volts form the circuit, preventing the latch relay from activating till we trip the key sense wire again
Last edited by WhiteRabbit; Mar 3, 2006 at 01:43 PM.
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Rep Power: 812 hmm as long as i crank in 2 secs or less the deck doesn't turn on til after the car starts. i thought most decks had a time delay feature.
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Rep Power: 337 I can't remember what color it is.
to determine key sense is easy, with a multimeter. there are only so many harnesses on the steering column, but I remember it being on the right next to the IGN harness. its a small wire.
nab a multimeter and ground one lead. use the other lead as a probe and sense DC voltage with it. from my earlier writeup, it seems that the wire is hot, then drops to ground with the key in. so you will be looking for a 12 volt signal. when you find it, insert the key and see if the voltage drops to zero.
if it does? youve got the wire!
to determine key sense is easy, with a multimeter. there are only so many harnesses on the steering column, but I remember it being on the right next to the IGN harness. its a small wire.
nab a multimeter and ground one lead. use the other lead as a probe and sense DC voltage with it. from my earlier writeup, it seems that the wire is hot, then drops to ground with the key in. so you will be looking for a 12 volt signal. when you find it, insert the key and see if the voltage drops to zero.
if it does? youve got the wire!
i boogie for the raindrops
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From: Jackson, Mississippi
Rep Power: 0 damn steve, you still post on here?
i've got some radio control aux alarm fun for you.
get yourself the universal pac steering wheel control interface, the one with the IR repeater. well, since we have no steering wheel controls, have fun with aux alarm channels...
even more fun, get yourself a remote controlled 12v relay board, and use more than one pac interface. can we say conplete stereo control from a distance?
pac part
http://www.logjamelectronics.com/pacswisteerw.html
relay board with 10 channels...
http://www.electronickits.com/kit/co...lec/ck1618.htm
headlights, stereo, dome lights, windows....
possibilities are endless...
i've got some radio control aux alarm fun for you.
get yourself the universal pac steering wheel control interface, the one with the IR repeater. well, since we have no steering wheel controls, have fun with aux alarm channels...
even more fun, get yourself a remote controlled 12v relay board, and use more than one pac interface. can we say conplete stereo control from a distance?
pac part
http://www.logjamelectronics.com/pacswisteerw.html
relay board with 10 channels...
http://www.electronickits.com/kit/co...lec/ck1618.htm
headlights, stereo, dome lights, windows....
possibilities are endless...
Last edited by LudlamTheory; Sep 22, 2006 at 04:50 PM.
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Rep Power: 337 I started posting here again recently. I found a series of design related posts. the audio forums are great and all, but noone talks about design there. only equipment and that gets real old, real fast. Singlehandedly what makes this forum so great. Single handed.
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Rep Power: 269 Dude, did you find my keyless "key sensor" wire yet!? J/k ( don't have a multimeter with me so i haven't been able to check it yet), but ur diy is great and a great idea...i've often wondered about the radio kill while being cranked...
Last edited by redrocket600; Sep 24, 2006 at 02:06 AM.
