Trunk Lights Not Working

[raiderfan247365]

If you've seen my other recent thread you know that I am in the process of swapping "almost" all my car bulbs to LED. What I just realized though is that my trunk lights do not turn on and there appears to be no power coming from the leads. I have literally replaced every fuse in the car recently but just for kicks, does anyone know which fuse specifically controls the trunk light? The owners manual doesn't go that granular.

Let's say it isn't the fuse, is there a trigger in my trunk/wiring somewhere that tells the lights to turn on when the trunk is open? I know the lights used to turn on and I do have a bad lock actuator, new part will be here tomorrow, any thoughts on if that could be my issue. All other lights in the interior are functional fyi, it's just the trunk lights.

 

[Brian J. Patterson]

I'm just guessing right now since my Town Car is on the other side of town and I don't have the service manual (which includes schematics) yet. I'll go out on a limb and guess that the trunk light switch is part of the actuator, since I didn't see a switch anywhere else. So, check it after the new actuator is installed. This is also a gentle hint to someone who does have the schematics to say that "Fuse X" protects the trunk light, and the switch is located at [wherever it's located.]

Thanks in advance.

 

[raiderfan247365]

I'm just guessing right now since my Town Car is on the other side of town and I don't have the service manual (which includes schematics) yet. I'll go out on a limb and guess that the trunk light switch is part of the actuator, since I didn't see a switch anywhere else. So, check it after the new actuator is installed. This is also a gentle hint to someone who does have the schematics to say that "Fuse X" protects the trunk light, and the switch is located at [wherever it's located.]

Thanks in advance.

Can confirm my lights work after replacing actuator Thanks!

 

[Bambam89]

Don't mean to bring up a 2+ year old thread but I am having the exact same issue. Pardon the ignorance but what/where exactly is the "actuator"? Thanks.

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[raiderfan247365]

Don't mean to bring up a 2+ year old thread but I am having the exact same issue. Pardon the ignorance but what/where exactly is the "actuator"? Thanks.

Hey there @Bambam89, the actuator I referred to is the trunk lock actuator. It connects to your trunk right behind the area where you put the key in.

 

[Brian J. Patterson]

Hello again, thread.

I've noticed that like almost every other light on the '98-end Town Car, the Lighting Control Module is involved. If your LCM is acting "flaky" otherwise, it may also be causing troubles with your trunk light.

On my '01 Lincoln Town Car, the map lights will (temporarily so far) quit working at the same time the trunk light does. Both "come back," indicating a LCM "going south," without enough "cab fare" to make the trip and stay.

I'm still lazy and "schematic-free." So I'll guess that the trunk light switch is in the trunk lock actuator assembly. So, if your lights are otherwise well-behaved, you can either replace the trunk lock actuator assembly, or remove it, clean the contacts on all switches inside it, and reinstall.

Good luck.

 

[Bambam89]

Thank you for the quick replies gentlemen, so the actuator is the assembly connected to the key lock cylinder (correct term?).

The only light I had before was the light on the taillight side before it stopped working. I noticed a something dangling on the fuel door side and just found out it's supposed to be a light as well, was just pulled out without a bulb. When I attempted to put the plastic back in the housing I noticed a spark when the metal bulb holder came into contact with the metal body of the car. I took the bulb out of the taillight side trunk light and put it in the fuel door side...still no light. HOWEVER, when the metal part of the bulb holder came into contact with the body the light came on! I tried snapping a picture while holding it in place. I am by no means an electrician or mechanic but looks like a there is a break in the circuit somewhere, all the LCM related fuses look good...could this be a wiring issue or do yall still think it may be the actuator?



On a side note, it seems like my air suspension light came around at the same time and is now sagging. Jumping the connector with a paperclip did not work. Is it possible this is related to the trunk lights not working? Man, I really want to love this car but chasing new electrical problems sure ain't fun less than a week into ownership much less trying to fix the existing ones.

 

[Bambam89]

Replaced the DDM last week and the trunk latch actuator today...trunk still does not open without key and still no lights. Just about ready to give up on this thing because I'm mad at myself for wasting $100 on the actuator which I was sure would at least fix the light or the non-opening issue. Even put a new trunk pull down fuse in the engine compartment but still no luck. Any ideas how to trouble shoot? As shown in the picture above, the side trunk light will come on if I touch the metal bulb holder to the car body metal, but it'll stay on permanently and not turn off when the trunk closes.

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[raiderfan247365]

Replaced the DDM last week and the trunk latch actuator today...trunk still does not open without key and still no lights. Just about ready to give up on this thing because I'm mad at myself for wasting $100 on the actuator which I was sure would at least fix the light or the non-opening issue. Even put a new trunk pull down fuse in the engine compartment but still no luck. Any ideas how to trouble shoot? As shown in the picture above, the side trunk light will come on if I touch the metal bulb holder to the car body metal, but it'll stay on permanently and not turn off when the trunk closes.

Sorry to hear about your troubles, believe me when I say that I've been there. Question, does your trunk now close all the way, like the pull down motor pulls it to fully closed position?

 

[Bambam89]

Sorry to hear about your troubles, believe me when I say that I've been there. Question, does your trunk now close all the way, like the pull down motor pulls it to fully closed position?

No it does not, I have to close the trunk manually. The car does have an automatic trunk open/close along with the pull down but none of them work...which I am OK with, I just wanted the ability to unlock the trunk with the key fob or button on the door along with the trunk lights. Had I known this new part would have been useless, I would have just left things the way they were...the $5 motion sensor led light I attached works perfectly however, I should have just left it at that!

 

[raiderfan247365]

No it does not, I have to close the trunk manually. The car does have an automatic trunk open/close along with the pull down but none of them work...which I am OK with, I just wanted the ability to unlock the trunk with the key fob or button on the door along with the trunk lights. Had I known this new part would have been useless, I would have just left things the way they were...the $5 motion sensor led light I attached works perfectly however, I should have just left it at that!

Yea, it sounds like you may have some electrical issues, especially considering that the one light only works when you ground it on the frame. The powered trunk feature on these cars is a common issue for owners, I've been through the entire trouble shooting process before. The thing about the powered trunk feature is that it consists of three parts: lock actuator, pull down motor, and trunk lid motor. If either the actuator or pull-down motor is malfunctioning, the power lock may not work. For me, replacing the actuator did the trick.

And clarification, when I asked if your trunk gets pulled down all the way, I didn't mean from a fully open position. When you close your trunk, it should "soft close" and then the pull-down motor activates and closes it completely, like an inch or so?

 

[Bambam89]

Yea, it sounds like you may have some electrical issues, especially considering that the one light only works when you ground it on the frame. The powered trunk feature on these cars is a common issue for owners, I've been through the entire trouble shooting process before. The thing about the powered trunk feature is that it consists of three parts: lock actuator, pull down motor, and trunk lid motor. If either the actuator or pull-down motor is malfunctioning, the power lock may not work. For me, replacing the actuator did the trick.

And clarification, when I asked if your trunk gets pulled down all the way, I didn't mean from a fully open position. When you close your trunk, it should "soft close" and then the pull-down motor activates and closes it completely, like an inch or so?

I understood ya, maybe I should have been more clear. No "soft close" either, it's as if there is no power coming to any part of the trunk except when I ground the bulb holder to the frame for the light. After reading your post and several others with the similar problem, I was so sure that the actuator would have fixed it. Bummed out because it feels like $100 just flushed down the toilet so I'll consider it a lesson, maybe that money would have been better spent having a professional diagnose it. I'm OK not having a power trunk, maybe I'll just get a 2nd key made so I don't have to shut off the car to open the trunk, how much do they typically go for?

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[M1Greg]

My response from previous trunk closure post:

"I had an issue with the pull down motor in my 2004 not working. The latch assembly has two micro switches that tell the DDM if the trunk (latch ) is in the up or down position. This does a couple of things. The DDM then signals the Lighting module to turn on/off the trunk lights and it also sends a signal to the the instrument cluster to alert trunk ajar. I managed to replace a damaged diode in the pull down module to get my motor working so I now have lights and soft close feature."

My Pull down module was in the trunk under the pull down actuator. You have the power open option so your module may be in a different location or there even might be multiple modules. My point is there is an interplay of mechanical / electrical systems at work just to get the trunk lights to turn on / off. Without an electrical schematic and a parts location diagram it's hard to troubleshoot your problem.

 

[Bambam89]

My response from previous trunk closure post:

"I had an issue with the pull down motor in my 2004 not working. The latch assembly has two micro switches that tell the DDM if the trunk (latch ) is in the up or down position. This does a couple of things. The DDM then signals the Lighting module to turn on/off the trunk lights and it also sends a signal to the the instrument cluster to alert trunk ajar. I managed to replace a damaged diode in the pull down module to get my motor working so I now have lights and soft close feature."

My Pull down module was in the trunk under the pull down actuator. You have the power open option so your module may be in a different location or there even might be multiple modules. My point is there is an interplay of mechanical / electrical systems at work just to get the trunk lights to turn on / off. Without an electrical schematic and a parts location diagram it's hard to troubleshoot your problem.

Interesting. How did you determine it was a bad diode in the pull down module? Do you know if that trunk needs the power open motor to work in order to just "pop" open using the button on key fob or door? I hear a slight clicking in the door panel when I press the trunk button (maybe relay?) but nothing happens.

 

[etinpa]

I don't have wiring diagrams for the 2008 but I do for the 2009 which should be very close. Maybe these will help.

As M1Greg thought, the pull down module does not exist in your car. With the power decklid option the switches in the pull down unit go to the LTM (Liftgate/Trunk Module). The pull down module functionality is integrated into the LTM.

Having the trunk light work when grounded is normal. Power to the trunk lights come from the "Demand Lighting" output of the LCM which is always on except when in "battery saver" mode (it turns off about 30 minutes after the car is shut off in case some courtesy lamps were left on). The LCM controls the trunk lights by connecting wire 707 to ground.

If you want a separate key just for the trunk, it doesn't need to be a chipped "PATS" key. Any hardware store can copy your key onto a "dumb" blank for a couple of bucks. That key will work for trunk and doors. Just don't put that key in the ignition. It will piss off the security system!

Good luck!

 

[Bambam89]

Thank you and everyone else so far for the detailed info so far. Does the "dumb" key have to be a certain size or shape and do hardware stores typically carry them in stock?

As for the trunk lights, I replaced the bulbs with LEDs and connected a small piece of wire from the driver side light to ground to the body so the light turns on while the trunk is open. I know the lights will stay on when the trunk closes but hopefully only for 30 minutes at most as you mentioned. Worst case they might stay on overnight...do ya'll think this will drain the battery overnight to the point the car won't start? Hoping that the LEDs help by drawling less power.

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[raiderfan247365]

Thank you and everyone else so far for the detailed info so far. Does the "dumb" key have to be a certain size or shape and do hardware stores typically carry them in stock?

As for the trunk lights, I replaced the bulbs with LEDs and connected a small piece of wire from the driver side light to ground to the body so the light turns on while the trunk is open. I know the lights will stay on when the trunk closes but hopefully only for 30 minutes at most as you mentioned. Worst case they might stay on overnight...do ya'll think this will drain the battery overnight to the point the car won't start? Hoping that the LEDs help by drawling less power.

Obviously your mileage will vary depending on battery size and health. But those small LEDs shouldn't be too bad on the battery in a worst case scenario.

 

[M1Greg]

Something to try before hard wiring the ground to the trunk lights. Find the VT-Wht wire (circuit 1605 in the the power decklid 2 diagrams etinpa supplied) The wire is to one of the two microswitches on the striker assembly. ( trunk latch behind the key ) Momentarily ground it with a jumper wire and see if the lights come on. this would indicate the signaling portion of the PWR Decklid module is passing it's signal to the Lighting Control module to turn the lights on. If this works, you could just rig a striker switch to the trunk lip that would close the circuit when the trunk is open. Better on the battery for sure.

 

[etinpa]

As far as the "dumb" key is concerned, most (all?) hardware stores carry the blanks since they were used in the Ford trucks that didn't have PATS which was long after all of the cars got chipped keys. My 2009 E-250, for instance, uses a "dumb" key even for the ignition and the same blank would work for your dumb Lincoln key.