Sorry, had trouble getting the circuit diagram on the original post.



141767-Modified toggle circuit.jpg

 

Excellent, informative post-- I look forward to the pics [img]/w3timages/icons/smile.gif[/img] Good job... now want to come do that to mine?

G

2003.5 Black w/ Willow G35
Premium / Sport / Aero / Winter / Navi / Tint

 

Awesome idea. With some pictures, we can move this thread to FAQ/DIY. [img]/w3timages/icons/smile.gif[/img] (I'd move it now, but then you couldn't post any pictures.)

2003.5 G35 Sedan Desert Platinum/Graphite Premium/Sport/Aero/Nav/Winter

 

Thanks for the positive feedback. As I've said, I'm glad I am able to contribute something for all the help you guys have given me. Rather than taking apart my car again, I will be doing this mod for a friend of mine who is just now ordering all the parts and components. I will be taking pictures of each of the steps once he gets all the components, so it may take a while, but I am determined to document this for the rest of you. Thanks again.

 

This is great info! It could be very useful for, potentially, switching between inputs if the NAV input is modified. Thanks for the post!

 

I'm going to make this sticky for now so it doesn't get lost. mohdds: when you get those pictures ready, PM me and we'll get this moved to the FAQ/DIY forum.

2003.5 G35 Sedan Desert Platinum/Graphite Premium/Sport/Aero/Nav/Winter

 

Re: Mod for those with HomeLink
Updated Information (very long)

I originally posted a modification which would allow utilization of the HomeLink buttons to control/switch up to three devices in your car. As previously posted, I utilize one of the buttons to switch the continuity of the VSS signal to the NAV unit on or off. Some other ideas for the use of this mod is 1) a remote power switch to a computer or other device, 2) switch between various inputs to the NAV screen, 3) as a convenient mirror mounted switch to control courtesy, mood or other lights, 4) to toggle on or off any other device that can be connected to a relay.

Since I neglected to take photographs of my original install, I was waiting for parts to arrive so that I could take photos of an install I was going to do for a friend. The bad news is that my friend accidentally ordered/received the wrong model of RF receiver. The great news is that it turns out that this RF receiver greatly simplifies implementation of this mod.

The original purpose of this modification was to convert a garage door receiver to change it from providing a momentary on type switch function, to a latching on/off switch function which can then be utilized to control/power/switch what ever device you desired. Unfortunately, this required some electronic hobbyist skills to fabricate a high current MOSFET toggle switch (with debouncing circuit) on the momentary on contacts of the garage door receiver (I included a circuit diagram in my previous post).

Rather than the cheaper universal garage door receiver unit (momentary on only contact), my friend accidentally ordered the DesignTech “hobbyist receiver model #30037” that provides this latching function. The great news is that in contrast to what I was originally told by DesignTech, it actually provides three separate channels of control rather than just one, so that despite the higher cost ($83.95 as SmartHomeUSA.com), only one of these units would be needed to accommodate up to three devices! More importantly, it makes this modification easily doable by even the most electronically “challenged” enthusiast.

Because this receiver model #30037 provides a switching transistor controlled latching output (to ground), instead of having to build a separate MOSFET toggle switch for each device your wish to control, all you have to do is to attach a relay with a current rating compatible with the device you wish to power/control. There are three wires coming out of this receiver, each of which provides a separate switched ground contact. You connect the ground end of the relay coil to this wire, and provide a positive 12 VDC source to the other coil contact. You then wire the relay’s switched contacts (NO or NC) depending on what you are trying to control. E.g., for my application, the VSS to NAV wire (white wire w/green stripe on terminal #8 of the white colored 24 pin “M57” connector on the back of NAV Control Unit) would be connected to the NC (normally closed) contacts. When the relay coil is energized by pushing one of the HomeLink buttons on your rear view mirror, the relay would open the contacts, tricking the NAV into believing your car was not moving, allowing you to access the longer menus and input data into your NAV. After accessing/inputing whatever information on your NAV, pressing the HomeLink button again reconnects the VSS wire and returns your NAV to normal operation.

The following paragraphs include detailed instructions from DesignTech on how to program and connect the receiver (with my modifications in italics and underlined):

v0.1
Model 30027
GENERAL PURPOSE REMOTE CONTROL SYSTEM
With 3 Transistor Outputs

This system provides the ability to control 3 separate items with three styles of outputs
-- momentary, sustaining and latching. Range is typically 200 to 300 feet with the best
range being when the white antenna wire is 'high and in the clear' -- or the most exposed.

12 volts DC must be provided to the 12VDC 50mA jack on the side of the receiver’s case. To minimize the length of wire runs and number of connections to your car to simplify installation, find a 12VDC source which is switched on with the ignition (e.g., tap the + contact on the back of the auxiliary (cigarette lighter style) power outlet on the passenger side of the console; terminal with red wire w/black stripe; according to the service manual it is also protected by its own 15 amp fuse in the No. 5 position in the Fuse Block/Junction Box located behind the dash side lower driver side finisher panel). Ground can be established at a ground point right next to where you place the receiver, or can be tapped off of the ground wire (black) to the power outlet. If you use a “double spade” type connector to the back of the power outlet, you don’t have to cut any wires nor damage the factory wires with crimp type wire taps. Use a power plug (2.1 mm ID and 5.5 mm OD barrel type coaxial power plug available from Radio Shack) and solder the ground wire to “tip”, and the positive wire to the outer barrel. Reversing these contacts may result in damage to your remote control system.

SETTING THE RELAY OUTPUT MODE
You can choose one of three types of relay outputs, indicated by how many times the
red LED flashes when in the programming mode described at the end of this section:

To utilize the receiver to control a relay to “latch” between continuity of the VSS to NAV, or to turn on or off power to a device, the relay output mode must be set to “Latching”.

* Momentary (1 flash) - a 130 millisecond relay closure. Use this setting for
normal pulse type applications.
* Latching (2 flashes) - closes the external relay until you tap the button
again. Use this setting for turning on and off a lamp or appliance (or the VSS to NAV connection!)
* Sustaining (3 flashes) - closes the external relay for as long as you hold
down the transmitter button.
The system’s Green, Orange and Yellow output wires are all negative
transistor outputs and must be used to drive relays which in turn can
drive your desired output.
Your system is factory-set to the Momentary relay output mode for normal operation.
Follow these steps to change the output mode:
1. Tap and hold the white button on the side of the receiver until you see the red LED
flash the number of times that corresponds to the desired relay output mode.
2. Release the button at the desired mode.
Notes:
* If you continue holding down the button, the receiver continues cycling through
the modes until you release the button.
* You can change the relay output mode at any time without affecting the “learned”
transmitter codes.
All three outputs of the Green, Orange and Yellow are the same. They are all transistor
outputs and must drive external relays.

The Green wire responds to the left button.
The Orange wire reponds to the middle button,
The Yellow wire responds to the right button.
Here is an example of how to use an external relay to control your desired operation:
Connect the output wire of the Model 30027 to one of the two coil sides of the relay
chosen. Connect the other side to the positive power supply. If you were using a
relay with a 12 volt coil -- you would then hook this other side of the relay coil to +12
volts. You would hook it to 24 volts if you had a 24 volt relay coil etc. Now when
ever the Model 30027 output wire activates to the transistor ground state -- you will
'activate' the relay.
You need to hook the relay's common, normally open and normally closed relay
contacts up as necessary to perform the desired operation.
Code Learning: If your receiver module does not respond to your transmitter, or if you
purchase additional transmitters:
1) Tap and release the white/gray button on the side of the receiver with a pen. (The red
LED on the receiver will flash 4 times.)
2) Within the next 4 seconds, tap the left transmitter button down and hold it until the red
LED on the receiver module flashes once (about 4 seconds). Release the transmitter
button.
3) If you have more than one DesignTech transmitter, immediately tap and hold the left
button on the next transmitter, as in step 2 above, after you have released the button on
the first transmitter. (Hold this button until the LED on the receiver flashes once).
Do this with all the transmitters -- up to 4 -- that you have.
4) Finally, wait approximately 5 to 10 seconds until the LED on the receiver flashes 3
more times and your system will be ready for use.

(end of DesignTech programming instructions)

The only other modification (besides the power adapter plug) I made to DesignTech’s instructions was to place a diode across the coil contacts as a countermeasure to prevent surge voltages from the coil from damaging the switching transistor in the DesignTech receiver. The reason this is necessary is that if the coil current is suddenly interrupted, a sudden high voltage pulse is developed in the coil. If this voltage exceeds the voltage resistance of the transistor, the transistor will be degraded, and this will lead to damage. It is necessary to connect a diode in the circuit as a means of preventing damage from the counter emf. As suitable ratings for this diode, the current should be equivalent to the average rectified current to the coil, and the inverse blocking voltage should be about 3 times the value of the power source voltage. A 1N914 switching diode should be adequate for this application.

For switching the VSS signal to NAV off and on, I utilized a small 12VDC DPDT DIP relay rated at 2 amps with a 12vdc 740 ohm coil. This relay is very small (0.80” x 0.38” x 0.40” high) and fits into a standard 16 pin IC DIP socket for ease of replacement. I went with a small and quiet relay because I didn’t want to hear a loud click from the relay every time I activated the relay. Of course, if you are utilizing the relay to provide power to a device, the relay must be rated for the current draw of whatever device you are providing power to. The reason I used a dual pole, dual throw relay was so I could attach a bi-color (green/red) indicator LED to one pair of contacts, and the VSS to NAV wire to the other pair. In order to again simplify the wiring of this LED, it should be a three lead bi-color LED as opposed to a two lead bi-color LED (two lead bi-color LEDs rely on reversing the direction of voltage to change colors which necessitates wiring in an additional relay; three lead bi-color LEDS have a common cathode and two anode leads, one for each color, which will greatly simplify wiring).

The DPDT relay will switch the VSS to NAV wire and the power to the LED in tandem so that the bi-color indicator LED will glow green when the NAV unit is in normal mode (relay coil un-powered, VSS wire in normally closed position), and red when the VSS circuit is “open”, allowing you to input or access information on the NAV from the long menus with the vehicle in motion. This indicator LED is useful as I don’t always have the NAV screen out, but I want to be sure that continuity of the VSS wire to the NAV is intact so that the gas mileage log and maintenance interval logs are maintained and are reasonably accurate. If this modification is used to provide power to a device, you may want to reverse the leads on the indicator LED so that the default color is red (indicating no power to your device), changing to green when power is provided.


As you can see, this circuit is much simpler than having to build/solder your own MOSFET switch. One relay will be needed for each channel (up to three) you decide to use.

After all connections are made, provide power to the modified receiver device by turning on your ignition switch to the acc position, and program the receiver to the RF transmitter according to the DesignTech instructions above. Then, program the appropriate HomeLink button you wish to use with this mod utilizing the instructions provided in your G35 manual (you can program up to three separate channels). Finally, test out your system by using the HomeLink button to confirm that everything works (press once to disengage VSS from NAV, press again to re-engage).

Again, the advantages of this modification are that 1) it is very stealthy, 2) you do not have to route any wires to add additional switches (especially difficult depending on where you want to place the switches), 3) modification can be easily unplugged from the factory harnesses (except for the one cut VSS wire) when turning in leased cars, or if you should ever have a problem with the NAV/audio system in the future and you are still under warranty (the only telltale sign in my car—it was purchased outright for cash and is not leased-- is a small LED indicator in the center console above the hazard light button).
Another cool feature of this mod is that even if you do not have the HomeLink system in your car (or already use all three HomeLink buttons), you can still control the receiver with the three button key FOB transmitter (for a real cool install I would take the key FOB transmitter apart and incorporate someplace in the car—the advantage being you still don’t have to run wires to the buttons so you can place the small transmitter anywhere you want, even on the steering wheel if you wish!).

By the way, I’m looking into Nissan/Infiniti’s terminal connector repair kit which is used by the dealerships to repair damaged connectors on their electrical harnesses (Infiniti connector and terminal pin kit #J38751-95INF). The connector to the NAV unit is a 24 pin white connector designated as “M57” in the service manual. If the proper male and female connectors are available for the terminal joint connector on the back of the NAV unit, a short adaptor harness can be made to fit between the NAV unit and the factory harness and NO wires would have to be cut (this would be great for those who wish to add the Avelectronics unit to send other video sources to the oem LCD display screen!). Unfortunately, although the connector for the harness end is probably available, I seriously doubt that a female connector like the one on the NAV unit itself is available.

I will try to post photos along with step-by-step instructions when I get a chance.











144133-VSS circuit mod.JPG

 

WoW !!!!!!!! Great Post, Dont know how to do all the things that wre said, But thanks for the info, sure people on here also apreciate it

=)

Discreet

2003.5 Ivory Pearl Coupe 5AT

 

Very good idea!
Just a question, my G do not have the homelink... If I found the the driver mirror with homelink he system can be used? In other words how I can have homelink likes he original one, the buttons on the mirror.

Thanks,
Xat

 

My HomeLink "mod" requires no direct modification of the HomeLink system itself. It is only a receiver which will respond to the RF signal that your HomeLink unit emits. Therefore, my receiver mod will work with any HomeLink transmitter unit, whether it came with your G, or whether you add it via the mirror unit available directly from HomeLink as an aftermarket install (it will also work in any make of car which comes with a HomeLink unit as well). No modifications to the HomeLink unit itself is needed, which makes this an easy modification to transfer between cars at the end of your lease, or if you sell your car.

 

Ok,
Then the whole Homelink system is in the mirror. I think that Infiniti used Gentex NVS Part #50-GENK40.

Xat

 

I really wish I could use that homelink on my mirror but the apt building I live in had a magnetic key I have to carry around in my car.

Anyone got any suggestions how or what else one could use for those buttons?

 

does anyone know if this wireless switch will work with the homelink

http://www.sounddomain.com/shop/item.pl?sku=PILPLSW29

 

Awesome....Definitely on my list of Mods to do once it warms up a bit...Thanx for this comprehensive post.

 

I have a suggestion. The harness connecting to NAV unit is itself made of plastic (I presume). In my experience, the actual wires are cramped onto metal pins which are then inserted into the harness. (These pins usually have a reverse latch to lock them in place.) With a piece of thin but stiff wire inserted into the harness at the right place, individual pins/wires can be pulled out of the harness.

Since the pins are standardized you can probably find compatible harnesses for which both male and female are available. That way the VSS wire can be tapped into without any actual cutting. Do you know what I mean? What do you think?

Few more questions:

Can you elaborate why the diode is necessary? Is it for when opening the relay coil circuit, when induction causes a reverse flow of electricity? So the diode shorts it out?

Are you sure that the gas mileage and maintenance interval logs are independent of the odometer? I always thought these logs read off of the odometer computer.

You wrote:

By the way, I’m looking into Nissan/Infiniti’s terminal connector repair kit which is used by the dealerships to repair damaged connectors on their electrical harnesses (Infiniti connector and terminal pin kit #J38751-95INF). The connector to the NAV unit is a 24 pin white connector designated as “M57” in the service manual. If the proper male and female connectors are available for the terminal joint connector on the back of the NAV unit, a short adaptor harness can be made to fit between the NAV unit and the factory harness and NO wires would have to be cut (this would be great for those who wish to add the Avelectronics unit to send other video sources to the oem LCD display screen!). Unfortunately, although the connector for the harness end is probably available, I seriously doubt that a female connector like the one on the NAV unit itself is available.

http://www.imagestation.com/member/?name=bsoo