How JustAnswer Works:

  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.

Ask Davo Your Own Question

Davo
Davo, Master technician
Category: Chevy
Satisfied Customers: 3253
Experience:  ASE Master Technician also L1 Advanced Engine Performance Specialist
Type Your Chevy Question Here...
Davo is online now
A new question is answered every 9 seconds

1993 Corvette Headlight Problem

Customer Question

I have a 1993 conv corvette with a headligh problem. When the headlight are turned on the motor keeps on working for about 10 seconds (thump thump noise). I replaced the headlight module in the front of driver side motor compartment and it still makes the noise and now the headlights open when the parking lights are selected on the switch. Do you have any suggestions?
Submitted: 8 years ago.
Category: Chevy
Expert:  marc replied 8 years ago.

1. Check the wiring at the headlight door control module. Check for voltage on the Blue/White wire at terminal C with the headlight switch off and 0 volts when the headlight switch is in Park or headlight position.

2. Check the Yellow wire at terminal (A) should have 0 volts with the headlamps switched off and in the Park position. Battery voltage should appear when the headlamp switch is in the headlamp position.

3. Check for a good ground at terminal D.






Customer: replied 8 years ago.
Reply to marc's Post: I should also mentioned that when I plug in the old headlight module the lights open and close in the correct position when selected on the the switch in the car. But the motors keep on making noise. So how do you stop the motors when the headlights are open. As I said it keeps on making this noise for about 10 sec after the headlights are open and closed.
Expert:  marc replied 8 years ago.

Did you check the ground at (D) The test are still the same, The headlight doors recieve power thru the module you have to see why the module is not opening and closing the motor circuit at the proper times.


Still all boils down to terminals A,C or D.


I'm betting on a conection problem in the ground circuit.

Customer: replied 8 years ago.
Reply to marc's Post: I think I may have found a problem with the part I obtained from the dealer. The control module I was given from the GM dealer has a part number 16521297 and the old control module has a part number of 16509737-2. I called the dealer bbut they are closed for the weekend. Do you think that this is the problem?
Expert:  marc replied 8 years ago.

Let me do a little research


Also am checking somthing else out the motor should shut it self off not the module. I am trying to find out what is suposed to stop motor.


Will see what I can find .

Customer: replied 8 years ago.
Relist: No answer yet.
I need to find out what controls the motor to the headlights. I was told that the headlight control module controls the motors. This is why I bought a new headlight module. When I install the new module it will not stop the motors from running and now the headlight open when I select the parking lights. The original headlight module did not do this. I can put back the old headlight module and the lights work proberly but the motors continue to operate for about 10 seconds. The new module does not operate the headlights as the old module. I need to correct the initial problem of why does the headlight motor continue to run after it is closed or opened for 10 seconds. It makes a thump thump noice during this operation.
Expert:  Davo replied 8 years ago.
I tend to agree with Marc.You need to follow the black wire from terminal D it's entire length and check for corrosion or a loose connection.Connections must be taken apart to be checked not just eyeballed.There is a splice indicated inthe wiring diagram.They are famous for corrosion issues.When doing the voltage checks that look for power it should be close to battery voltage not 2 or 3 volts lower.
Customer: replied 8 years ago.
Reply to Davo/diablo666's Post: Hey guys sorry not getting back with you but had to find some more time to work on car. Well I did not find any shorts in the wire; I even ran another wire and made sure it was to ground. This did not work. Yesterday I decided to take apart the headlight actuator and found my problem. The gear in the actuator was worn, not the gear itself but the drive notch on the back of the gear. I was expecting to see the teeth worn but it was the notch in the back of the gear. This explains the thump thump noise. It made a thump noise every time the square drive slipped on the nylon gear on the back side of the gear. As for my headlight module I have an extra module for sale. I will try to take it back to my Chevy dealer. I do not expect to get my $175.00 back. Thanks for your help anyways!

JustAnswer in the News:

 
 
 
Ask-a-doc Web sites: If you've got a quick question, you can try to get an answer from sites that say they have various specialists on hand to give quick answers... Justanswer.com.
JustAnswer.com...has seen a spike since October in legal questions from readers about layoffs, unemployment and severance.
Web sites like justanswer.com/legal
...leave nothing to chance.
Traffic on JustAnswer rose 14 percent...and had nearly 400,000 page views in 30 days...inquiries related to stress, high blood pressure, drinking and heart pain jumped 33 percent.
Tory Johnson, GMA Workplace Contributor, discusses work-from-home jobs, such as JustAnswer in which verified Experts answer people’s questions.
I will tell you that...the things you have to go through to be an Expert are quite rigorous.
 
 
 

What Customers are Saying:

 
 
 
  • I was having a terrible problem with the wheel bearings on my 98 Chevy Cavalier and I suspect that using this website saved me plenty of time and money. Todd L Rochester NY
< Last | Next >
  • I was having a terrible problem with the wheel bearings on my 98 Chevy Cavalier and I suspect that using this website saved me plenty of time and money. Todd L Rochester NY
  • Wonderful service, prompt, efficient, and accurate. Couldn't have asked for more. I cannot thank you enough for your help. Mary C. Freshfield, Liverpool, UK
  • This expert is wonderful. They truly know what they are talking about, and they actually care about you. They really helped put my nerves at ease. Thank you so much!!!! Alex Los Angeles, CA
  • Thank you for all your help. It is nice to know that this service is here for people like myself, who need answers fast and are not sure who to consult. GP Hesperia, CA
  • I couldn't be more satisfied! This is the site I will always come to when I need a second opinion. Justin Kernersville, NC
  • Just let me say that this encounter has been entirely professional and most helpful. I liked that I could ask additional questions and get answered in a very short turn around. Esther Woodstock, NY
  • Thank you so much for taking your time and knowledge to support my concerns. Not only did you answer my questions, you even took it a step further with replying with more pertinent information I needed to know. Robin Elkton, Maryland
 
 
 

Meet The Experts:

 
 
 
  • Tim's Auto Repair

    mechanic

    Satisfied Customers:

    7641
    Have owned a repair shop for 25 yrs.
< Last | Next >
  • http://ww2.justanswer.com/uploads/TI/tim37857/2011-10-28_23053_S6301814.64x64.JPG Tim's Auto Repair's Avatar

    Tim's Auto Repair

    mechanic

    Satisfied Customers:

    7641
    Have owned a repair shop for 25 yrs.
  • http://ww2.justanswer.com/uploads/DT/dt69nova/2012-6-15_234154_pic1.64x64.jpg Dave Nova's Avatar

    Dave Nova

    Chevrolet Technician

    Satisfied Customers:

    6870
    ASE Master Certification. GM World Class Certification
  • http://ww2.justanswer.com/uploads/ggrote1/2009-06-27_031011_me.jpg Gary's Avatar

    Gary

    Chevy Technician

    Satisfied Customers:

    5404
    15 years GM master tech
  • http://ww2.justanswer.com/uploads/testedtuff/2009-09-26_170108_pictures.jpg John's Avatar

    John

    Master A.S.E Automotive technician

    Satisfied Customers:

    4071
    A.S.E MasterTechnician A1-A8 w/L1,38 years experience General Motors Master Technician
  • http://ww2.justanswer.com/uploads/RO/rodcuda/2011-7-25_224114_Donhoff1.64x64.JPG Neal's Avatar

    Neal

    Chevy Mechanic

    Satisfied Customers:

    2306
    Shop Owner and Mechanic on multiple makes.
  • http://ww2.justanswer.com/uploads/goodwrench9124/2008-11-09_220838_dscf0007.jpg goodwrench9124's Avatar

    goodwrench9124

    ASE Certified Technician

    Satisfied Customers:

    2041
    Ase Master Certified, GM Master Certified Tech. Awarded GM Top performer, Hybrid certified
  • http://ww2.justanswer.com/uploads/DR/drivefast1971/2012-1-12_172422_0009051tQKh.64x64.jpg Ron Z.'s Avatar

    Ron Z.

    - Chevy Tech -

    Satisfied Customers:

    1912
    18+yrs experience. State Inspector and Chevy Diagnostics