GMC

GMC troubleshooting questions? Ask a mechanic for answers

Ask an Expert,
Get an Answer ASAP!

GMC Yukon Denali: The headlights in 1999 Denali are not switching…

Customer Question
The headlights in 1999 Denali...
The headlights in 1999 Denali are not switching on automatically. I can manually switch on the lights. Once I manually turn on the lights, the relay sounds like it is trying to switch over...I hear a constant, rapid clicking from under the dash. Also, while the apparent relay is trying to engage, there is a slight rapid pulsing of the headlights. The clicking of the relay will randomly stop and start with no particular reason for it to start and stop. When I take this issue to the dealer, as with may electrical issues, it never shows up so it goes unrepaired (The GMC dealer also doesn't seem to understand that it is supposed to switch over on this model year). I also cannot determine where the clicking is coming from under the dash. Suggestions
Submitted: 3 years ago.Category: GMC
Show More
Show Less
Ask Your Own GMC Question
Answered in 3 days by:
7/6/2015
GMC Mechanic: Pete, GMC Mechanic replied 3 years ago
Pete
Pete, GMC Mechanic
Category: GMC
Satisfied Customers: 33,303
Experience: GM training and dealer tech for 14+ years. Diagnostics
Verified
My name is ***** ***** I am a professional here at Just Answer. I noticed that your question was not getting a response and thought I would see if you still need help with this.I apologize for the delay and I hope I can still assist you with this here.
This model should have a DRL (day time running lamp) control module under the dash that is common to fail and can cause this here.I have had to replace this module before for this issue here.
Thanks Pete
Ask Your Own GMC Question
Customer reply replied 3 years ago
Thank you Pete. I am going to look into replacing the DRL module. Is there a way to locate the module under the dash. I am not sure I have a 'Map" of its location as I am sure there are several modules under the dash. How do I determine which one it is?
GMC Mechanic: Pete, GMC Mechanic replied 3 years ago
Is the dash indicator coming on near the gauges to let you know the day time lamps are on?It usually looks like a light/picture of a light being on.
Let me know,thanks Pete.
Ask Your Own GMC Question
Customer reply replied 3 years ago
Thanks for the response Pete. I am out of town for a couple of days so will get back to you shortly after I return.
Customer reply replied 3 years ago
Pete,
The answer to your question about the dash indicator is no, it is not coming on. I replaced the diode today but that has not solved the problem. I have read that there is a circuit board under the dash but don't know where to find it...could that be the problem? or the relay?
GMC Mechanic: Pete, GMC Mechanic replied 3 years ago
I apologize for the delay.I was on vacation for a bit there.
Was the diode the component under the dash that you had replaced?
Ask Your Own GMC Question
Customer reply replied 3 years ago
Yes, I replaced the diode under the dash. Still no change and I have ordered the circuit board that is also under the dash. As I previously indicated, the green light on the dash does not come on.
GMC Mechanic: Pete, GMC Mechanic replied 3 years ago
O.k.,the drl module is located under the dash to the far left/drivers side of the dash as seen in the links below.Since the diode did not correct this issue I suspect the module is the cause here.The diode is usually most common to fail that's why I suggested it first.
https://www.dropbox.com/s/mrz1o85dvx3ucub/drl-07-27.gif?dl=0
https://www.dropbox.com/s/qow192ev5p1juj9/drl1-07-27.gif?dl=0
Thanks Pete
Ask Your Own GMC Question
Was this answer helpful?

How JustAnswer works

step-image
Describe your issueThe assistant will guide you
step-image
Chat 1:1 with a gmc mechanicLicensed Experts are available 24/7
step-image
100% satisfaction guaranteeGet all the answers you need
Ask Pete Your Own Question
Pete
Pete
Pete, GMC Mechanic
Category: GMC
Satisfied Customers: 33,303
33,303 Satisfied Customers
Experience: GM training and dealer tech for 14+ years. Diagnostics

Pete is online now

A new question is answered every 9 seconds

How JustAnswer works:

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

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:

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!!!!

AlexLos 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.

GPHesperia, CA

I couldn't be more satisfied! This is the site I will always come to when I need a second opinion.

JustinKernersville, 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.

EstherWoodstock, 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.

RobinElkton, Maryland

He answered my question promptly and gave me accurate, detailed information. If all of your experts are half as good, you have a great thing going here.

DianeDallas, TX

< Previous | Next >

Meet the Experts:

Gm Tech (Cam)

Gm Tech (Cam)

GMC Mechanic

1,796 satisfied customers

GM Grand Master Technician 2007. 14 year experience.

Gary

Gary

ASE Certified Technician

1,588 satisfied customers

GCM master tech over 25 years

Dave Nova

Dave Nova

GMC Technician

929 satisfied customers

ASE Master Certification. GM World Class Certification

Chris (aka-Moose)

Chris (aka-Moose)

GMC Technician

626 satisfied customers

16 years of experience

Ron Z.

Ron Z.

- GMC Tech -

279 satisfied customers

18+yrs experience. State Inspector & GMC Diagnostics/Repair

JFN1

JFN1

ASE Certified Technician

270 satisfied customers

GM Master Technician

George H.

George H.

ASE MasterTechnician

228 satisfied customers

15+ Years ASE Master Technician with Level 1 Certification

< Previous | Next >

Related GMC Questions
I️ have a 2003 Gmc Envoy my headlights randomly shut off as
I️ have a 2003 Gmc Envoy my headlights randomly shut off as I'm driving. I️ have already replaced the relay. I'm looking for someone to walk me through the steps of diagnosing and fixing this problem.… read more
eauto
eauto
self employed
High School or GED
74 satisfied customers
2007 Yukon Denali voltmeter up and down while parked or
2007 Yukon Denali voltmeter up and down while parked or stoped- headlights and dash lights mimic the pulsing. Battery dies randomly. Nobody knows how to fix it. Alternator test comes back good and bat… read more
Gary
Gary
ASE Certified Technician
Vocational, Technical or Trade Scho
1,588 satisfied customers
The headlights wont go off, bulbs are fine and working -
bulbs are fine and working - have not checked fuses - looking through manual to figure out which one controls the lights … read more
Brandon
Brandon
93 satisfied customers
I have a 2006 GMC Envoy Denali. I have no air flow from the
I have a 2006 GMC Envoy Denali. I have no air flow from the dash vents. I bought a new mode actuator and installed it. I followed the calibration steps however, I'm now getting a clicking noise which … read more
Alan Hatcher
Alan Hatcher
4 satisfied customers
I change my headlight last night. Every work and it even started
I change my headlight last night. Every work and it even started before I put it back to together. … read more
JFN1
JFN1
ASE Certified Technician
Vocational, Technical or Trade Scho
270 satisfied customers
GMC Yukon Denali: , I have a 2000 GMC Yukon Denali. It is
Hi, I have a 2000 GMC Yukon Denali. It is an OBS 5.7L. I'm fairly certain that the ignition switch has gone out from prior research; last summer the truck randomly started flashing lights, turning the… read more
Dave Nova
Dave Nova
GMC Technician
Associate Degree
929 satisfied customers
GMC Sierra 1500 WT Crew Cab: My 2014 GMC Sierra has a new style
My 2014 GMC Sierra has a new style headlight with only two wires to the single headlight bulb. I am trying to locate the wire that controls the -beam/low-beam shutter.… read more
JFN1
JFN1
ASE Certified Technician
Vocational, Technical or Trade Scho
270 satisfied customers
GM YUKON DENALI: I have a 2000 GMC Denali Yukon. A while back,
I have a 2000 GMC Denali Yukon. A while back, I started hearing occasional "clicking" in the dash board and then began to develop problems with not having dash lights sometimes when I start the truck … read more
Chris (aka-Moose)
Chris (aka-Moose)
GMC Technician
Vocational, Technical or Trade School
626 satisfied customers
GMC Sierra 1500: Hello. I have installed a prostart ct-3371
Hello. I have installed a prostart ct-3371 into my 1996 GMC Sierra. Everything works except the unlock/lock function.. It starts fine via remote and shuts off with remote and brake pedal. I have conne… read more
molurch
molurch
Owner
Vocational, Technical or Trade Scho
941 satisfied customers
Thank goodness I found you!!!! I, too, have a 1999 Denali
Thank goodness I found you!!!! I, too, have a 1999 Denali that is having headlight issues. I have daytime running lights. but the moment is gets dark, I lose all headlights!!!! I have running side lig… read more
Chris (aka-Moose)
Chris (aka-Moose)
GMC Technician
Vocational, Technical or Trade School
626 satisfied customers
GM 2011 Savana: I recently purchased a 2011 GMC Savana SE limited
I recently purchased a 2011 GMC Savana SE limited 1500. I have noticed some things that I am not used to seeing that may be a problem, and one thing that is a problem. (1) The engine turvoer rate is n… read more
sprinkles08
sprinkles08
Technician
High School or GED
11 satisfied customers
GMC Yukon Denali: 2011 Yukon XL Denali Both Front seat heaters
2011 Yukon XL Denali Both Front seat heaters stopped working Yesterday. I used to hear the relay click when I turned on and also when switching settings. Don't hear it anymore. Lights on the door modu… read more
Chris (aka-Moose)
Chris (aka-Moose)
GMC Technician
Vocational, Technical or Trade School
626 satisfied customers
GMC Yukon Denali: I have a 2003 GMC Yukon Denali, and just
I have a 2003 GMC Yukon Denali, and just the other day randomly my keyless remote stopped working. But not just that, the radio immediately turns off after the engine is off when that normally stays o… read more
Dave Nova
Dave Nova
GMC Technician
Associate Degree
929 satisfied customers
GMC Yukon: 2007 GMC Yukon Denali will not start. Does not
2007 GMC Yukon Denali will not start. Does not even attempt to turn over. Battery is fine. Started fine just a hour or two earlier. Parked it, and now it won't turn over. Acts like it is not in Park, … read more
Dave Nova
Dave Nova
GMC Technician
Associate Degree
929 satisfied customers
GMC Envoy Denali: I have a 2006 GMC Envoy Denali, with only
I have a 2006 GMC Envoy Denali, with only 58k miles. Both low beam headlights turn off occasionally for periods of 3-20 minutes, with all other lights working that I am aware of. Could this be the fus… read more
Dave Nova
Dave Nova
GMC Technician
Associate Degree
929 satisfied customers
GMC K1500 Sierra 4x4: I have a 2005 GMC Sierra 1500 Z-71. The
I have a 2005 GMC Sierra 1500 Z-71. The interior dome light works with the dash switch, but won't come on when the door is open. But, when I remove the key from the ignition, then the light comes on. … read more
Dave Nova
Dave Nova
GMC Technician
Associate Degree
929 satisfied customers
GMC Yukon XL 1500 Denali: I have 06 GMC Yukon XL Denali It
I have 06 GMC Yukon XL Denali It was hit in the left front and has been repaired, but the streeing wheel lock won't work, it has a click all the time when your turning the wheel. Where is the locking … read more
Gm Tech (Cam)
Gm Tech (Cam)
GMC Mechanic
Vocational, Technical or Trade Scho
1,796 satisfied customers
GMc 1500 Series: I have a 1999 GMC serria 1500 sle v8. instument
I have a 1999 GMC serria 1500 sle v8. instument pannel lights do not come exept for the shift indicator. radio lights and a/c lights also do not come on. also the headlights flash on an off while driv… read more
Dave Nova
Dave Nova
GMC Technician
Associate Degree
929 satisfied customers
Disclaimer: Information in questions, answers, and other posts on this site ("Posts") comes from individual users, not JustAnswer; JustAnswer is not responsible for Posts. Posts are for general information, are not intended to substitute for informed professional advice (medical, legal, veterinary, financial, etc.), or to establish a professional-client relationship. The site and services are provided "as is" with no warranty or representations by JustAnswer regarding the qualifications of Experts. To see what credentials have been verified by a third-party service, please click on the "Verified" symbol in some Experts' profiles. JustAnswer is not intended or designed for EMERGENCY questions which should be directed immediately by telephone or in-person to qualified professionals.

Disclaimer: Information in questions, answers, and other posts on this site ("Posts") comes from individual users, not JustAnswer; JustAnswer is not responsible for Posts. Posts are for general information, are not intended to substitute for informed professional advice (medical, legal, veterinary, financial, etc.), or to establish a professional-client relationship. The site and services are provided "as is" with no warranty or representations by JustAnswer regarding the qualifications of Experts. To see what credentials have been verified by a third-party service, please click on the "Verified" symbol in some Experts' profiles. JustAnswer is not intended or designed for EMERGENCY questions which should be directed immediately by telephone or in-person to qualified professionals.

Show MoreShow Less

Ask Your Question

x