Headlight doors
Thread Starter
Intermediate
Joined: Oct 2010
Posts: 33
Likes: 0
From: Lima Ohio
Headlight doors
I am trying figure out an inop headlight door on a 2001 c5 (both sides) and i need to know what the voltages are for the connector c1 for pin (a) (white wire) and pin 3 (c) dk green wire. I suppose it may be different for headlight on and off. Any one know?
Is this a question for Bill Curlee? Can anyone help here?
Is this a question for Bill Curlee? Can anyone help here?
Last edited by dmills324; Nov 11, 2010 at 10:41 PM. Reason: need help...post has been up a couple days
Instructor
Joined: Oct 2010
Posts: 240
Likes: 2
From: Yangpyeong Gyeonggi-Do
A (white wire) B+ headlight on
C (drk grn wire) B+ headlight off
Battery Positive voltage is applied from the HDLP circuit breaker in the instrument panel fuse block to both the coil and switch side of the ALC HDLP relay 44. When the BCM receives this signal it will apply a ground to the coil side of the ALC HDLP relay 44. This energizes the relay, closing the switch, and applies battery positive voltage to the headlamp switch and to the headlamp opening door actuator control module. This actuator allows battery positive voltage from the HDLP MOT LH fuse and HDLP MOT RH fuse in the underhood electrical center to be applied to the headlamp opening door assemblies. The ground circuit is applied from G102.
C (drk grn wire) B+ headlight off
Battery Positive voltage is applied from the HDLP circuit breaker in the instrument panel fuse block to both the coil and switch side of the ALC HDLP relay 44. When the BCM receives this signal it will apply a ground to the coil side of the ALC HDLP relay 44. This energizes the relay, closing the switch, and applies battery positive voltage to the headlamp switch and to the headlamp opening door actuator control module. This actuator allows battery positive voltage from the HDLP MOT LH fuse and HDLP MOT RH fuse in the underhood electrical center to be applied to the headlamp opening door assemblies. The ground circuit is applied from G102.
Thread Starter
Intermediate
Joined: Oct 2010
Posts: 33
Likes: 0
From: Lima Ohio
thanks for the info. I was beginning to think no one would answer me. I will check this stuff out and hopefully find something.
I have replaced the module with a supposedly good one from ebay.The steering wheel is off and the MFS seems ok, I am checking it out. My wife just had rotator cuff surgery so my time has been limited.
Is the relay 44 replaceable?
I have replaced the module with a supposedly good one from ebay.The steering wheel is off and the MFS seems ok, I am checking it out. My wife just had rotator cuff surgery so my time has been limited.
Is the relay 44 replaceable?
Instructor
Joined: Oct 2010
Posts: 240
Likes: 2
From: Yangpyeong Gyeonggi-Do
there are several relays that are the same. may be able to swap it with another for troubleshooting. just check the numbers on the relays closely. #44 is replaceable, just unplug and install new one..... Instrument panel fuse block
Instructor
Joined: Oct 2010
Posts: 240
Likes: 2
From: Yangpyeong Gyeonggi-Do
Might want to check and make sure the BCM is sending a ground to energize relay 44. Only thing in common to both headlight doors are the MFS, BCM, Relay 44 and the door actuator control module.
Good luck
Good luck
Thread Starter
Intermediate
Joined: Oct 2010
Posts: 33
Likes: 0
From: Lima Ohio
Headlights come on. I swapped relays (44)and it still did not open (headlight doors). Connector C1 is correct except the green wire does not have B+. Doors open if I connect battery voltage and a ground to Connector C2.
Would you happen to know what terminal on the relay would be the ground that you suggestI check?
Thanks for your help and suggestions
Would you happen to know what terminal on the relay would be the ground that you suggestI check?
Thanks for your help and suggestions
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
2027 Corvette vs The World: Every C8 vs Its Closest Competitor
Joe Kucinski
Thread Starter
Intermediate
Joined: Oct 2010
Posts: 33
Likes: 0
From: Lima Ohio
headlights
I used to think I was pretty good at figuring car stuff out but this has me stumped. C1 is correct (on the meter) except the "off" signal wire the green "c", so why doesn't it open the doors, just not close them. Is it possible that the off input signal is bad AND the headlight module..
I really can't figure out how to check to see if the BCM is sending the ground by the schematics bryonhunter replied with. Does anyone know what terminals are what for relay 44 to see if the ground is being applied.\Is a BCM going bad a common thing?
Thanks\Dan
I really can't figure out how to check to see if the BCM is sending the ground by the schematics bryonhunter replied with. Does anyone know what terminals are what for relay 44 to see if the ground is being applied.\Is a BCM going bad a common thing?
Thanks\Dan
Last edited by dmills324; Nov 24, 2010 at 09:07 AM. Reason: clarification
Tech Contributor
Joined: Dec 2006
Posts: 10,962
Likes: 29
From: Van Buren Arkansas
Wounded Warrior Escort '11
Melting Slicks
Joined: Oct 2007
Posts: 2,383
Likes: 13
From: Kinston North Carolina
Thread Starter
Intermediate
Joined: Oct 2010
Posts: 33
Likes: 0
From: Lima Ohio
door closes????????????
A (white wire) B+ headlight on
C (drk grn wire) B+ headlight off
Battery Positive voltage is applied from the HDLP circuit breaker in the instrument panel fuse block to both the coil and switch side of the ALC HDLP relay 44. When the BCM receives this signal it will apply a ground to the coil side of the ALC HDLP relay 44. This energizes the relay, closing the switch, and applies battery positive voltage to the headlamp switch and to the headlamp opening door actuator control module. This actuator allows battery positive voltage from the HDLP MOT LH fuse and HDLP MOT RH fuse in the underhood electrical center to be applied to the headlamp opening door assemblies. The ground circuit is applied from G102.
C (drk grn wire) B+ headlight off
Battery Positive voltage is applied from the HDLP circuit breaker in the instrument panel fuse block to both the coil and switch side of the ALC HDLP relay 44. When the BCM receives this signal it will apply a ground to the coil side of the ALC HDLP relay 44. This energizes the relay, closing the switch, and applies battery positive voltage to the headlamp switch and to the headlamp opening door actuator control module. This actuator allows battery positive voltage from the HDLP MOT LH fuse and HDLP MOT RH fuse in the underhood electrical center to be applied to the headlamp opening door assemblies. The ground circuit is applied from G102.
so what happens when the lights are turned off.Does the BCM play a part in sending a signal. Should the headlight doors open even if the green at the HDM does not read correct
Melting Slicks
Joined: Oct 2007
Posts: 2,383
Likes: 13
From: Kinston North Carolina
dmills, 12 volts on the white wire opens the doors, 12 volts on the green wire closes the doors. Both are fed from the Headlamp Switch. The BCM dosn't affect it if the Twilight Sentinel is turned off. I cannot quite figure if your's "won't open," "won't close," or "won't do either." Give us a better description of the problem.
Thread Starter
Intermediate
Joined: Oct 2010
Posts: 33
Likes: 0
From: Lima Ohio
Headlight doors won't go up or down.Motors work up or down when i apply positive voltage to the individual wires going to the motors. I have a 2001 z06 so twilight sentinal was not an option or if it was I don't have it. "On" signal works (white wire on c1) but "off" signal does not (green wire C1).all other wires read correctly in the meter. Where does the off input come from? BCM?
