Back-up lights illuminated entry

[Dereck]

Hi Guys

I've noticed a lot of the newer vehicles put the back-up lights on when the trunk/tailgate is opened or with the illuminated entry feature when the car is unlocked and thought I might have a go at reworking the back-up lights on my Marauder to do the same.

So the design brief was for the back-up lights to come on when the trunk is open and as an illuminated entry feature when the car is unlocked at night and the parking/head/courtesy lights come on.

At first I thought it would be a simple job with a couple relays but I ran into a problem, the trunk light ground wire has voltage on it from the LCM untill switched to ground when the trunk is opened, which basically meant I had to add an extra relay, here is my wiring schematic for you to critique.



http://superstitiongold.com/lincoln/pictures10/2003%20Marauder%20Back%20Up%20 Light%20With%20Deck%20Lid%20Li ght%20Take%202.JPG



There is one minor fly in the ointment I am working on at the moment and that is the courtesy lights fade as they turn off which means the upper right relay coil loses voltage gradually and buzzes for 1/2 a second as it trys to switch with a low voltgae, as the relay is buzzing it means the contacts will be arcing, not a good thing for relay longevity, I am thinking this may be cured with a capacitor across the relay coil.

Regards

Dereck

[EMAS]

Having a capacitor in the system to provide that fade away effect is what is causing the problem of the buzzing relay adding another will only extend the time that the relay buzzes.

[dmjarosz]

How about using a solid state relay? Low power ones can be purchased for pretty cheap. Im gonna run this plan past my electrical engineer friends and see if we cant solve the noise problem.

Your diagram looks good to me. I like where your head's at with this idea.

[dmjarosz]

Are the parking lighs always on when driving at night with the headlights? The only problem I see with that diagram is if I turn the dome light on while driving at night, the reverse lights will come on. Not good.

[Dereck]

Hi Emas


Having a capacitor in the system to provide that fade away effect is what is causing the problem of the buzzing relay adding another will only extend the time that the relay buzzes.

I was thinking maybe reduce the relay coil voltage to a minimum required for the coil to hold using a resistor and then a capacitor would maybe reduce the "buzzing" with a little extra voltage before the voltage drops off completely as the courtesy lights fade


Hi Dmjarosz


Are the parking lighs always on when driving at night with the headlights? The only problem I see with that diagram is if I turn the dome light on while driving at night, the reverse lights will come on. Not good.

Yes the back-up lights would come on if you switched the dome lights on while driving at night but this would only happen if you used the main light switch to do it, which I expect you would virtually never need to do as the rear seat passengers can switch thier dome/reading lamps on indipendently and the front seat passenger/driver can switch thier light on using the switch in the roof console.

Regards

Dereck

[EMAS]

Where in the circuit are you planning to put the capacitor and resistor?

[Dereck]

Hi Emas


Where in the circuit are you planning to put the capacitor and resistor?

The resistor/capacitor thought has been shelved due to calculations revealling an unfeasonably large capacitor would be required, plan B is to use a Schmitt trigger and then maybe making the whole circuit solid state.

Regards

Dereck

[dmjarosz]

Yes the back-up lights would come on if you switched the dome lights on while driving at night but this would only happen if you used the main light switch to do it, which I expect you would virtually never need to do as the rear seat passengers can switch thier dome/reading lamps on indipendently and the front seat passenger/driver can switch thier light on using the switch in the roof console.

I use the main switch to do it all the time. What about some sort of normally-closed relay on the dark green wire in your diagram that opens when the car is shifted out of park? That would prevent the reverse lights from coming on when the car is moving. Is there something on the transmission circuit that could be tapped?

What newer vehicles do you see that have this feature? It would be nice to get a wiring diagram and see whats going on from the factory.

[EMAS]

What newer vehicles do you see that have this feature? It would be nice to get a wiring diagram and see whats going on from the factory.

GMs are the ones I've seen with that feature.

[Mr. Man]

Wouldn't it be easier to just add a few more courtesy lites around the car and have them come on with the push of the unlock button?

I would think the added glare from reverse lites would make rummaging around in the trunk a pain. Might be better to just add some extra lites in the trunk for rummaging. JM:twocents: :)

[fastblackmerc]

Wouldn't it be easier to just add a few more courtesy lites around the car and have them come on with the push of the unlock button?

I would think the added glare from reverse lites would make rummaging around in the trunk a pain. Might be better to just add some extra lites in the trunk for rummaging. JM:twocents: :)

When the trunk lid is open the reverse lights are pointing up. How will that help with looking in the trunk or lighting up around the rear? Would be much easier to add LEDs to the inside of the trunk and maybe some under the rear bumper.

[Mr. Man]

When the trunk lid is open the reverse lights are pointing up. How will that help with looking in the trunk or lighting up around the rear? Would be much easier to add LEDs to the inside of the trunk and maybe some under the rear bumper.
Isn't that what I said :confused:

[fastblackmerc]

Wouldn't it be easier to just add a few more courtesy lites around the car and have them come on with the push of the unlock button?

I would think the added glare from reverse lites would make rummaging around in the trunk a pain. Might be better to just add some extra lites in the trunk for rummaging. JM:twocents: :)


When the trunk lid is open the reverse lights are pointing up. How will that help with looking in the trunk or lighting up around the rear? Would be much easier to add LEDs to the inside of the trunk and maybe some under the rear bumper.


Isn't that what I said :confused:

Not exactly...... :)

[Mr. Man]

Not exactly...... :)
Pretty darn close. ;)

[ctrlraven]

When the trunk lid is open the reverse lights are pointing up. How will that help with looking in the trunk or lighting up around the rear? Would be much easier to add LEDs to the inside of the trunk and maybe some under the rear bumper.

That's actually what I was thinking. Most modern vehicles now, the reverse/back up lights are part of the body or taillights that are affixed to the sides of the trunk/lift gate.

[Dereck]

Hi Dmjarosz



What about some sort of normally-closed relay on the dark green wire in your diagram that opens when the car is shifted out of park? That would prevent the reverse lights from coming on when the car is moving. Is there something on the transmission circuit that could be tapped?

What newer vehicles do you see that have this feature? It would be nice to get a wiring diagram and see whats going on from the factory.

I realized the back-up lights would come on while moving if I put the dome lights on but as it is something I never do I didn't even consider a work around for the problem, I reckon an input from the TRS would probably work but it would require a little more wiring, will have to think about it.

As previously mentioned it seems to be mostly GM cars including Vauxhall, Opel and Saab on the European side of the pond and I am pretty sure I saw it on a Chrysler/Dodge vehicle, manufacturers now controll the lights with a computer so with a couple quick lines of code you can achieve just about any lighting combination you can think of.


Hi Mr Man



Wouldn't it be easier to just add a few more courtesy lites around the car and have them come on with the push of the unlock button?


I am not sure stringing in more lights would have been any easier than adding a few wires and relays but I wasn't after more light in the trunk.


Hi Fastblackmerc



When the trunk lid is open the reverse lights are pointing up. How will that help with looking in the trunk or lighting up around the rear?

It won't but as said I wasn't after more light in the trunk, I didn't do it for it's practicality more for it's aesthetic and gimmick value, when the trunk is closed though it happens to be a reasonably usefull feature to light your path whilst walking to the car.

I actually now have a rough draft of a solid state version of my schematic but it needs a little tweaking when I find out if the dome lights dimming is controlled with a capacitor or pulse width modulated, think I may also investigate adding an input so the back-up lights only come on whilst in park, seeing how I have been called out on it.

Regards

Dereck

[fastblackmerc]

Hi Fastblackmerc

It won't but as said I wasn't after more light in the trunk, I didn't do it for it's practicality more for it's aesthetic and gimmick value, when the trunk is closed though it happens to be a reasonably usefull feature to light your path whilst walking to the car.


The easiest way to do it is to add waterproof LEDs in pods or strips to the underside of the rear. Just wire them into the interior lights. Hardest thing would be running a wire to the harness that feeds the rear map lights.

[Mr. Man]

The easiest way to do it is to add waterproof LEDs in pods or strips to the underside of the rear. Just wire them into the interior lights. Hardest thing would be running a wire to the harness that feeds the rear map lights.
Actually I think the easiest way is to attach one of those intensely bright LED mini flashlights to his key chain. ;)

[dmjarosz]

I already added tons more lighting to my trunk. It was one of the first mods I did when I got the car. That stupid little light tucked way up under the deck does almost nothing for iluminating the Marauder's warehouse of a trunk.

[Dereck]

Hi Guys

Well here is the electronic control version of my "Back-up light illuminated entry" feature that addresses the problems associated with the original version that used relays.


http://superstitiongold.com/lincoln/pictures10/2003%20Marauder%20Back%20Up%20 Light%20With%20Deck%20Lid%20Li ght%20Electronic.JPG


The first problem was because the dome lights fade out using pulse width modulation at (from memory) 73Hz as they turn off one of the relays buzzed as it was trying to remain switched on a low voltage, obviously with no relays this no longer happens, the back-up lamps will now fade out in the same manner as the dome lights.

The second issue was if you switched the dome lights on using the main light switch whilst driving the back-up lights would come on, as you can see there is now an input from the neutral safety switch that only allows the back up lights to come on when in park or neutral.

However this circuit was designed partly with a Town Car in mind, when using it on a Marauder the starter relay will have to be removed and pins 30 & 87 bridged with a jumper wire, this obviously brings up another problem, allthough the car will be immobilized a crook could in theory crank the engine over until the battery was dead.

Hopefully in the next couple weeks this circuit will be built and tested on my Marauder, if not it will have to wait untill next spring as my car will shortly be going into hibernation for winter.

Regards

Dereck

[fastblackmerc]

IMHO, too complicated.... You must be an engineer.... :D:D

Why not just install LEDs in the trunk and a mercury switch? When you open the trunk the lights go on, just like the 2003 under hood light!

[RF Overlord]

Dereck, any particular reason you went with all IGFETs?

[Dereck]

Hi Fastblackmerc


IMHO, too complicated.... You must be an engineer.... :D:D

Why not just install LEDs in the trunk and a mercury switch? When you open the trunk the lights go on, just like the 2003 under hood light!

Why have simple when you can have an overly complicated useless feature no one wants?


Hi RF Overlord


Dereck, any particular reason you went with all IGFETs?

They have a low on resistance so won't get hot when passing the 4.5 amp load of the back-up lamps, one other thing if you were to actually build this circuit diode D3 should be mounted on a heatsink with a heat transfer co-efficient < 25°K/W

Regards

Dereck

[fastblackmerc]

Hi Fastblackmerc



Why have simple when you can have an overly complicated useless feature no one wants?




You really are an engineer! :lol:

[Dereck]

Hi Guys

Here it is the much anticipated Marauder back-up lights illuminated entry "module"

http://superstitiongold.com/lincoln/pictures10/2003%20Marauder%20Back%20Up%20 Light%20With%20Deck%20Lid%20Li ght%20Electronic%20Module.jpg


You may notice diode D3 (now called D5) is missing from the board, this is becuase during testing it got a little warmer than anticipated so its mounting needs to be tweaked slightly.

Regards

Dereck

[slickster]

Good job!!!!!! Now how much???

[lji372]

You really are an engineer! :lol:

:lol:

Have to say this is determination. Congrats on reinventing the wheel:bows:

[fastblackmerc]

:lol:

Have to say this is determination. Congrats on reinventing the wheel:bows:

His education as an engineer requires him to do that.

[Limited360]

His education as an engineer requires him to do that.

I'm an engineer. I don't require doing things like this...

:)

[Curless]

I'm an engineer. I don't require doing things like this...

:)


Yes, but as an engineer you were required to come over with Jerry Saturday...your engineering degree is now worthless in my eyes!:fishslap:

[Limited360]

Yes, but as an engineer you were required to come over with Jerry Saturday...your engineering degree is now worthless in my eyes!:fishslap:

Ok ok. You do have me there!! Guess I need to correct the mistake here soon!!

[Dereck]

Hi Slickster


Good job!!!!!! Now how much???

The components come in at under twenty dollars its the research and development that costs the big bucks.

Looks like I am probably not going to get this buttoned up before my Marauder goes into winter storage on the 28th, guess it will give me something to do next spring.

Regards

Dereck

[Dereck]

Hi Guys

Got the electronic control module all wrapped up, now just need to wait another 6 - 8 weeks before I go and retrieve my Marauder from winter storage.


http://superstitiongold.com/lincoln/2003MercuryMarauder/2003%20Marauder%20Back%20Up%20 Light%20Module%201.JPG


http://superstitiongold.com/lincoln/2003MercuryMarauder/2003%20Marauder%20Back%20Up%20 Light%20Module.JPG


Regards

Dereck

[ChiTownMaraud3r]

Nice work Dereck. As an EE I always enjoy when people take on projects especially on their cars. However I think it was way too much work for what you needed achieved.

For the trunk illumination I would have spliced the existing crappy trunk light to a couple of LED stripes and ran them to the opposite side of the reverse lights where they are not visible except when looking out from the inside of the trunk <- as previously stated by Jim.

If you want to achieve the reverse lamps coming on like GM cars when the interior lights are on, it can also be achieve with simple solid state logic gates. Actually an inverter and an AND gate to make it simple.
I would have take two signals.. 1 for interior light illumination (when car is unlocked) and another signal from the ignition ( I would tap the 12V only when car is on wire form the aftermarket harness on my radio.)

(Trunk lights) = (interior signal * ignition-NOT)

So your trunk lights come on when you have an interior signal high and while the car is off. The inverter will ensure the lights do not come on when the car is powered on(driving) and the interior is turned on. The circuit for the reverse lamps when in reverse will remain in place and does not change its current functionality since you would splice into the reverse lamps in parallel. A simple diode could be wired inline to the oem reverse lamps to ensure no reverse current leakage towards the LCM.

[Zack]

I have no idea what or why any of that was done.

One wire to ground, another wire to the positive of the trunk bulb.

[fastblackmerc]

The OP is an engineer........ need I saw more?

[ChiTownMaraud3r]

I have no idea what or why any of that was done.

One wire to ground, another wire to the positive of the trunk bulb.

He was going for the "I don't know if he's backing up or just unlocked his powered off car" thing chevy seems to have started... :rolleyes:

[Dereck]

Hi ChiTownMaraud3r

I don't think your propsed route will work as I desired.

My back up lights will now only come on...


In reverse :rolleyes:
With the trunk open
When the dome lights and parking lights are on (an illluminated entry feature)
If the shifter is in Park or Neutral

Regards


Dereck

[Dereck]

Hi Guys

Well I had a problem with the electronic control of my "Back-Up Lights Illuminated Entry" feature and have finally sorted it out.

It apppears that 28 - 32 minutes after switching the car off and with the trunk closed the voltage on the trunk light ground wire drops from battery voltage to a 5 volt reference, whether this is by design or not I do not know but I assume it a consequence of the battery saver feature, my electronic module was inturpreting this drop in voltage as a "trunk open" signal and switching the back-up lights on.

So below is the updated schematic, you will notice several resistors have changed value and the addition of a zenner diode in the trunk light ground input.


http://superstitiongold.com/lincoln/pictures10/2003%20Marauder%20Back%20Up%20 Light%20With%20Deck%20Lid%20Li ght%20Electronic%20Take%202.JP G



Regards

Dereck