trunk light

[edgemaster191]

ok here's the question...when i open the trunk on my beetle the little light in the dash does not come on saying the trunk is open, also the lil light in the trunk doesn't come on..this isn't a HUGE deal..but i was just wondering if it could be something as simple as the switch in teh trunk latch or maybe something mroe complex....just wondering if anyone had any idea's for me..thanks ppls!! :-D

ooh here's what it is
2000 New Beetle GLS
2.0L, 5 speed.

[bugwugvw]

no help for you, but i have the same car, same year, and same transmission and neither of mine work. hope you get an answer cause i want one too!

[who_me285]

My only guess would be the switch I dunno what else would go out

[Dick_Larimore]

I checked the Bentley manual wiring diagrams. One side of the lamp in the rear hatch is connected to a source of 12 volts. The luggage compartment light switch in the latch grounds the other side of the bulb when the hatch is open. The central control module for the comfort system monitors the connection between the lamp and the switch.

If the rear hatch release switch opens the trunk, the ground connection to the light compartment switch is likely to be OK. The most likely cause of the problem is that the luggage compartment lamp is burned out. Have you checked the lamp? If the lamp is OK, have you verified 12 volts is present on the center contact in the base of the bulb socket?

[hako]

Originally Posted by Dick_Larimore

I checked the Bentley manual wiring diagrams. One side of the lamp in the rear hatch is connected to a source of 12 volts. The luggage compartment light switch in the latch grounds the other side of the bulb when the hatch is open. The central control module for the comfort system monitors the connection between the lamp and the switch.

If the rear hatch release switch opens the trunk, the ground connection to the light compartment switch is likely to be OK. The most likely cause of the problem is that the luggage compartment lamp is burned out. Have you checked the lamp? If the lamp is OK, have you verified 12 volts is present on the center contact in the base of the bulb socket?

The wiring diagram also indicates that the "boot open" indicator lamp should be alight even if the boot light is burnt out. (boot=trunk)

[IHeartNB]

I have the same problems but my remote latch release works fine. I remember reading somewhere in the forum that the truck light is controlled by the microswitch inside the latch thats on the door and the dashboard indicator is controlled by a trunk sensor that I am not sure where to locate it. I can be completely offbase here Though I am also interested in finding out if there's a solution to this.

[Dick_Larimore]

The switch in the trunk latch does contol the lamp. There is no "sensor" in the latch that detects the trunk open. The signal is the voltage on the output of the bulb. The USA wiring diagram for the Beetle in my Bentley manual makes no mention that the rear hatch ajar light will function with a burned out lamp. If the light does not come on, have you checked to see if 12 volts is present in the bulb socket?

[IHeartNB]

The trunk lamp is functional since I put in a new one as the first course of action. And uhm, how do you test for the 12 volt? I was actually going to "try" and replace the microswitch if all failed. Thanks for the help.

[hako]

Originally Posted by Dick_Larimore

The switch in the trunk latch does contol the lamp. There is no "sensor" in the latch that detects the trunk open. The signal is the voltage on the output of the bulb. The USA wiring diagram for the Beetle in my Bentley manual makes no mention that the rear hatch ajar light will function with a burned out lamp. If the light does not come on, have you checked to see if 12 volts is present in the bulb socket?

Dick - The Haynes shows the boot light and the warning light being fed off the same 12V line and are wired in parallel so I'd presume that the warning bulb would still work....however I've been wrong plenty times before.

[Dick_Larimore]

Hako, I did pop the lamp out of my 2005 Beetle and I did confirm as you said that the bulb can be burned out and the hatch open warning light will still work.

I studied the diagrams in the Bentley manual some more and I think I understand the circuit now. The switch in the rear hatch has two contacts. One contact grounds one side of the luggage compartment lamp when the hatch is open. The other contact in the switch grounds the lamp on the dash and is also an input to the comfort control module. That module does all the door unlocking and mirror motor control. It is this module that powers the motor to unlock the rear hatch.

The problem with edgemasters Beetle is either caused by a bad switch in the latch module or the ground connection (brown wire connected to pin 2 of the switch) has broken. If I understand the schematics correctly, this small gauge ground wire connects to a larger brown wire from one on the unlatch motor. Both of these connect to an even larger brown wire that exits the hatch and is connect to the driver side C pillar above the rear wheel housing. Because the unlatch motor still works, the main ground lead that connects to the C pillar is OK. Any problem with the ground connection to the switch must be very close to the switch.

[edgemaster191]

well so far all i've tried is changing the bulb of the trunk light..no luck..no light in the trunk and no light in the dash...the remote unlock works fine as well as teh switch inside the car to open the trunk works fine...i think i'm going to to tear it apart this weekend and check the grounds...also there is a resister on the light bult assembly for the trunk light..i'ma test that too and see if ti's working...i'll update probably sunday night on my status..thanks for the input guys! i'm hoping it's just a loose ground *crosses fingers* if it's the micro switch depending on cost i may have to hold off for a while...

[IHeartNB]

so i was trying to locate the microswitch in the latch... didn't even get that far. there are two bolts securing the latch that i don't know what tool to use to open them. i've attached a photo below and hopefully someone can share some insight

[hako]

There's a great "How to" at this address:
http://www.newbeetle.org/forums/showthread.php?t=11237

[edgemaster191]

i wonder if it's just the lockplate sensor is bad...anyone have any thoughts on this? i pulled the trim piece off and looked at the locking system..wiring etc...nothing obvious..how would i go about testing if it's the lockplate sensor..if thats all it is then i'll be happy! thanks guys!

[Dick_Larimore]

There are at least two different wiring mechs for the new Beetle latch circuits. One is for the Beetle with the trunk mounted release switch and one for the newer cars without the switch. In all cases the wiring to the motor operated release switch is the same. The wire at pin 1 of the switch that connects to the luggage compartment lamp is brown with a blue stripe. The wire to pin 3 of the switch is brown with a black stripe and it goes to the central control module for the comfort system and the dash hatch light. The pin 2 of the switch is a brown wire and this connects to ground.

When the latch is unlocked, the switch contacts should close causing the wires at pin 1 and 3 of the switch to connect to pin 2 (ground). Grounding the wire at pin 1 will then turn on the luggage compartment lamp since the other side of the lamp is connected to 12 volts.

The wire on the luggage compartment lamp that goes to the latch switch is brown with a black stripe (the wires change color in a connector inside the rear lid). There should be 12 volts on the other side of the lamp (red with blue stripe). If you ground the brown/blue wire on the lamp, it should come on. Next, if you ground the wire on pin 1 of the latch switch (brown/blue), the lamp should again come on. One lead of a 12 volt test lamp can be connected to a source of 12 volts and the other lead connected to pin 2 of the latch switch. The lamp should light indicating the pin 2 is properly connected to vehicle ground. If these checks work as described, then the motor operated latch switch is defective.
.

[edgemaster191]

cool i'll give that a shot...i'm hoping it's just a bad ground and nothing major...i don't really wanna dump money into it (i've had it like 2 weeks...teh dealer wont' fix that though cause it "doesn't interfer with proper operation of the car or safety")

[Dallaslady]

I'm planning to print out ALL of the above to let my husband read it and hopefully see if it will help our problem. But in case it doesn't apply, here it is: a TRUNK issue, similar to the above (I think). I noticed my dash light indicating my trunk was open Friday, got out to check but it was fine. I loaded more stuff into my vehicle (from school), closed trunk and noticed light was off on the way home. However, once home, I couldn't open it at all. My key does NOT fit the trunk (I purchased it used and now believe they had the ignition and door locks changed) and don't have a remote (which was my next step). The gas tank release has never worked and neither has the trunk light (in the back). I can hear it trying to open at times. Sometimes it doesn't make a sound AT ALL. Prior to this I've also had a problem with my alarm not disengaging when unlocking the driver's side door (figured that was the latch problem). Are all of these things related, perhaps??? Help, please.

Thank you,

Dallaslady
Carrollton, TX
2000 NB 2.0, 5spd
Bug Driver since 1972

[turbofroggy]

The trunk light wasn't working in my Wife's 2001 NB. Bulb good, getting +12 to the bulb. Oh that is a diode in the bulb assembly, easy to check. (unhook bulb from connector, use meter on OHM setting, should be ~1 Ohm one direction, reverse your leads and it should be open the other direction.)

Checked the wires at the latch using the above mentioned technique, and figured out my latch switch is bad.

Very useful post, thank you!

[Miz Pea]

Originally Posted by Dallaslady

I'm planning to print out ALL of the above to let my husband read it and hopefully see if it will help our problem. But in case it doesn't apply, here it is: a TRUNK issue, similar to the above (I think). I noticed my dash light indicating my trunk was open Friday, got out to check but it was fine. I loaded more stuff into my vehicle (from school), closed trunk and noticed light was off on the way home. However, once home, I couldn't open it at all. My key does NOT fit the trunk (I purchased it used and now believe they had the ignition and door locks changed) and don't have a remote (which was my next step). The gas tank release has never worked and neither has the trunk light (in the back). I can hear it trying to open at times. Sometimes it doesn't make a sound AT ALL. Prior to this I've also had a problem with my alarm not disengaging when unlocking the driver's side door (figured that was the latch problem). Are all of these things related, perhaps??? Help, please.

Thank you,

Dallaslady
Carrollton, TX
2000 NB 2.0, 5spd
Bug Driver since 1972

Did you ever get your hatch light and alarm issues sorted? My 03 is doing the same thing. I haven't tried the gas lid - last I checked it, it worked. Got an appointment with my mechanic tomorrow but hoping it isn't going to cost an arm and a leg to fix!

[Miz Pea]

Originally Posted by Miz Pea

Did you ever get your hatch light and alarm issues sorted? My 03 is doing the same thing. I haven't tried the gas lid - last I checked it, it worked. Got an appointment with my mechanic tomorrow but hoping it isn't going to cost an arm and a leg to fix!

I DO have the original key, etc. Just have the problem of the rear hatch light on when it is closed and really hard to open with the remote or the door button. Also alarm goes off randomly.