Help! Headlight retraction Fault

[tfxman]

Looking for a little help. My headlights do not retract when the switch is returned to off. They will retract if the stalk is pressed forward as if to engage the high beams. During the fault there is ~9.fV with 0 Amp draw in the low beam circuit at the fuse box. After correction the circuit has 0V. The lights on warning chime also sounds during the fault. There is also a noise like a small fan or motor coming from below the right headlight. Once the fault is corrected or the low beam or parking light circuits are interrupted this disappears. My assumption is the Control Module uses the absence of voltage in the lighting circuits to signal the motor to retract. And requires a draw stronger than the parking circuits to extend. Hence the contradiction between when the doors engage (headlights, no parking) and retreat (no headlights OR parking).

 

[dadaroo]

The module has power at all times (Always Hot) for the motors and 2 fuses. The module gets a separate headlights ON or OFF voltage input and activates them accordingly.

The way the module is activated to Open is the BCM gets input as a result of the Multifunction Switch (MFS) operation and activates Relay 44 which in turn provides input voltage to the module to Open the doors. The loss of voltage causes the reverse to occur.

I can provide you the schematics if you can read them. Just PM me your year and email, since they are PDF files. All years work the same but just I case wire colors changed I need the year.

I think your issue is with the MFS but diagnostics can confirm. I think it is failing to open the circuit when turned OFF unless it is on high beam.

 

[tfxman]

Headlight, thanks for response.

I'd love to see the schematics. I'm a retired software engineer and I love diving into wiring harnesses. It's just another, easier state machine than the arcade hardware I used to work on. Please send me whatever you can, the car is a 2003 Z06 and my email is tfxman@mac.con. Thanks again for your rapid, and helpful response.
Tim

 

[Toms007]

Welcome tfxman to our little corner of the internet. Looks like Mr. Sam has you on the right path. We have some of the most knowledgeable and helpful people on any of the forums I've encountered. Stay around and you'll learn a lot and, hopefully, pass on the knowledge of these cars that you have acquired. That's what we're all about here.

 

[LLC5]

Looking for a little help. My headlights do not retract when the switch is returned to off. They will retract if the stalk is pressed forward as if to engage the high beams. During the fault there is ~9.fV with 0 Amp draw in the low beam circuit at the fuse box. After correction the circuit has 0V. The lights on warning chime also sounds during the fault. There is also a noise like a small fan or motor coming from below the right headlight. Once the fault is corrected or the low beam or parking light circuits are interrupted this disappears. My assumption is the Control Module uses the absence of voltage in the lighting circuits to signal the motor to retract. And requires a draw stronger than the parking circuits to extend. Hence the contradiction between when the doors engage (headlights, no parking) and retreat (no headlights OR parking).

I think dadaroo is right about your headlight switch being bad based on your description, but proper diagnosis is always the best way to determine the problem.


This has worked for me more than once, and since it's free it may be worth you trying it. Hold the stock of the switch with one hand (so as not to break the switch) and cycle the headlight switch through it's entire throw multiple times very fast, you can even try this using contact cleaner if you want to. Sometimes this will alter the contact pattern inside the switch enough to get the circuit to work. This wouldn't be a repair, just a quick headlight switch test if the problem goes away. Good luck with it.

 

[dadaroo]

Glad you want to learn the schematics, rarely do I hear that.

OK, I sent you 5 PDF documents that cover the headlights including the FSM description of the exterior lighting which you should find helpful. Rarely does just one schematic fully explain the overall design of a particular function.

You will notice that there are connectors that are identified staring with a C like C1, etc. You will also see there are connector terminal locations for each wire that my be A,B, C, etc or 1,2,3, etc.

Each connector should have these terminal locations denoted in the plastic mold but there are also connector end views in the FSM that can be very helpful. I did not send them but I can.


There is a "learning" process on how to figure out where one connector starts and another begins in the schematics since there can be several connectors going into a module.

I gave you my number and it would be easier to explain this since it is different based on what GM schematic style you are using. I can explain some other things also to give you a leg up.


Mr. Sam P. E.

 

[dadaroo]

Your email got kicked back. Double check what you gave me is correct.

 

[tfxman]

pdf files

Your email got kicked back. Double check what you gave me is correct.

address is always tfxman@mac.com
I'll make sure filters don't reject the upload

thanks
tim

 

[dadaroo]

Figured it out. You gave .con, not .com and I just clicked on it and didn't notice. Let me know when you get it. Sam

 

[MAC5]

tfxman,

Any chance you have HID headlights installed?

 

[tfxman]

could explain color

tfxman,

Any chance you have HID headlights installed?

Who knows what previous owners did. I have noticed the whiter color of the low beams and an odd projection cone. Didn't make sense w/ the bulb numbers being only one digit off. Pulling bulbs shortly, will let you know. Installed HID on motorcycle 13 years ago, must be simpler now or I'd have seen supporting hardware.

 

[MAC5]

Who knows what previous owners did. I have noticed the whiter color of the low beams and an odd projection cone. Didn't make sense w/ the bulb numbers being only one digit off. Pulling bulbs shortly, will let you know. Installed HID on motorcycle 13 years ago, must be simpler now or I'd have seen supporting hardware.

Do the head light assemblies look anything like this?

 

[tfxman]

yes, they do

Do the head light assemblies look anything like this?

View attachment 21232

large convex lens surrounded by chrome housing

 

[tfxman]

found the hardware

Do the head light assemblies look anything like this?

View attachment 21232

big ol thing, Sportiva makes the transformer
good installation, thought it was stock.
I'll try opening my eyes from now on.

are you familiar w/ door problem?
somebody mess up the low beam ground?

 

[MAC5]

Your low beam ballasts might be 35w or under 55w and not drawing enough current for the control module to detect them. That is why when you click on your high beams and then shut off the headlamps the headlight doors will close normally. The fix for this is usually to place a resister in the headlamp circuit. I'll have to search around on the other corvette forum site for the details on what resistors and where in the circuit to place them. I'll send you a couple of links to the articles when I find them. In the meantime, the quick fix is simply put your high beams on then shut the lights off.
Unless you can find out who and what HID system was installed you might have to do some calling to a couple of vendors to get there recommendations. JWMotoring and corvettemods originally sold the lower wattage systems and the resistors. I'd start with them first.

Vendor link for resistors
C5 Low Beam Inline Resistor- BLOWOUT SALE - JW Motoring

Headlight bucket issues with HID lighting, need direction - Corvette Forum


More as I find it.

 

[tfxman]

resistance is (not) futile

If your low beam bulbs are HID's your problem is due to the bulbs not drawing enough current for the control module to detect them. That is why when you click on your high beams and then shut off the headlamps the headlight doors will close normally. The fix for this is usually to place a resister in the headlamp circuit. I'll have to search around on the other corvette forum site for the details on what resisters and where in the circuit to place them. I'll send you a couple of links to the articles when I find them. In the meantime, the quick fix is simply put your high beams on then shut the lights off.

appreciate your help, wouldn't have thought of that. going to have to parse the logic (if any) Chevrolet uses to control(?) the motors. module knows enough to open but not enough to close. is this the Body Control Module at issue or have the computer happy engineers stashed another module somewhere?

 

[MAC5]

I suspect the issue is with the headlamp control module but can't say that for sure. I know this has been a known issue with some of the ACA HID mod's sold/installed over the years and if the quick fix of hitting the high beams corrects the problem and closes the headlamps, the missing resistor in the circuit usually permanently solves the problem. The ACA HID package that I installed came from a vendor who sources 70w ballasts so no additional resistors are required. Below are three links, two of which are to vendors who over time sold 35w and 55w ballast kits. They also sell the plug and play resistor. The third link is to another forum that I recommend you do a search on both the C5 general and technical sections using "headlight not closing" "HID headlight door not closing" you'll get numerous articles discussing your issue. I would recommend you try and figure out exactly what hardware you have, type bulbs, and ballasts and call both the vendors and discuss your issue with their tech people. They should be able to help you out with what resistor solution will work.

vendors:
Corvette Camaro Impreza Parts

Corvette Parts and Accessories | Corvette Mods LLC

forum:

C5 General - Corvette Forum

 

[tfxman]

another module heard, not seen from

the distinct humming noise (below right headlamp) during the fault must be the difficult to access (or even see) headlamp control module . An impressive diagnosis from 2000 miles away. Your help has been invaluable . I'll start pursuing these leads and keep you posted. Thank you again for the time you've spent on my behalf, I hope to pay it forward in the future.

I suspect the issue is with the headlamp control module but can't say that for sure. I know this has been a known issue with some of the ACA HID mod's sold/installed over the years and if the quick fix of hitting the high beams corrects the problem and closes the headlamps, the missing resistor in the circuit usually permanently solves the problem. The ACA HID package that I installed came from a vendor who sources 70w ballasts so no additional resistors are required. Below are three links, two of which are to vendors who over time sold 35w and 55w ballast kits. They also sell the plug and play resistor. The third link is to another forum that I recommend you do a search on both the C5 general and technical sections using "headlight not closing" "HID headlight door not closing" you'll get numerous articles discussing your issue. I would recommend you try and figure out exactly what hardware you have, type bulbs, and ballasts and call both the vendors and discuss your issue with their tech people. They should be able to help you out with what resistor solution will work.

vendors:
Corvette Camaro Impreza Parts

Corvette Parts and Accessories | Corvette Mods LLC

forum:

C5 General - Corvette Forum