Daytime running light circuit troubleshooting (DRL circuit) 

The camera work, the running commentary, the inset schematic with highlighting, the completeness of the vid -- probably the best I've seen period! THANK YOU for such an EXCELLENT tool!

Grateful to have come across these videos. I was able to diagnose, isolate and repair my non functional drl thanks to your walkthrough it's schematic. It is troubleshooting like this that not only separates the skilled from the novices but also teaches those with the desire and need to learn about their systems.

Excellent troubleshooting! This is what separates the men from the boys in our field of work. I've seen alot of "shooting from the hip" and parts changers over the years. Well done!

I been working on my 96 Hoe for sometime now and it is almost impossible to find good video references to repair her, your Videos are FANTASTIC! Thank you for doing such a great job!

Thank you, glad i could share this with you guys. many people have trouble understanding this even other techs i worked with over the years, hopefully this demonstration will help shed some light

Excellent, thank you, my wife was experiencing DRL warning lamp on and sliding doors not opening in her Honda Odyssey (youngest daughter jumped into the driver's seat as my wife was filling up with gas). Seeing in this video that there is connection from DRL to parking brake, I suggested to her to see if the parking brake was accidentally on a bit. That fixed the problem...nothing like diagnosing car problems from work over the phone =).

Keep up the good work! Your video made my life so much easier. It helped me diagnose an electrical issue in a SAAB. Jeez this was great!

Man that is some good controls troubleshooting! Really impressed at how thorough you are!

Excellent video - great camera control with added schematics from time to time, excellent instructions on both parts 1 & 2...it helped me diagnose that I had a faulty DLR relay and not the diode. The relay failed after I attempted to update my 1997 K1500 with replacement LED bulbs that were recommended for the vehicle. I'll be calling them tomorrow to see if I can even use the LEDs on my vehicle given what happened. I read some articles after I purchased my bulbs that you should not retrofit halgen based vehicles with LED bulbs as the cans are not designed for LED bulbs and the light does not get directed correctly and/or blinds on coming traffic.

i just wanted to say thank you for your videos on the day time running lights You help me narrow mine down to the relay switch and now my low beams work again. thank you agin.

Well done!! I recently bought the " load pro" test leads that connect to my DMM and in this situation it would work as you have shown with the push of a button. The test leads checks for opens, short to ground and high resistance all at once. A real time saver have a fantastic addition to my DMM I never remove. If you have never seen the load pro its well worth a review. Looking forward to part 2.

I forgot to mention, you were right. My Tahoe had a misfire in cylinder 1. It was the fuel injector. Thank you much. I am subscriber for life.

Thank you, im going to check that out Looks like a great setup. Part 2 will be up soon

Your electrical troubleshooting videos are very helpful. All your videos are great. Thanks for sharing.

Great job explaining the workings of this circuit and how to troubleshoot it and some of the pitfalls of using a multimeter.

As always one of your videos made troubleshooting a problem very simple.

Man your awesome!!!!! I have been trying to fix this for days until I watched your very easy to follow video. Thanks sooooooo much!!!👍👍

That was So thorough.., thank you so much. I'm taking electrical And having a hard time understanding it. But you broke down very well Can't wait for part 2!

Nice. The parking brake had fallen just enough to light the indicators. Pulled it up and the DRL is back in business. Thanks!

lol glad i could make your day a little better, thank you. That fancy test light is what came out of one of those Saturdays i had nothing better to do lol so i made a stubby test light with a needle point, that was over 5yrs ago one of the best tools in my box ;)

Thank you very much for the compliment :) glad the time of editing didn't go unnoticed... these circuits can get pretty tricky. understanding and reviewing the schematic is crucial My hope is some will study this and have a better understanding like you mentioned... you may be on the right track with the guess, im heading to the shop shortly if i have some time i would like look into the noise. thanks again,

90% of your tests at the relay...amen brother, haha. This is the reason why I love relays, because at the relay, you can quickly determine...1. how the coil is controlled(ground side switched or power side switched) 2. Bypassing the load terminals(if the circuit now works) you just ruled out the entire load side of the circuit. 3. Current draw can be measure there(load side) and so many other awesome tests, mostly with inexpensive tools anyone can purchase at Sears or some ma and pa hardware store. The fact that your test light was nice and bright at fuse 15 but was dim at the relay is an instant red flag. Obviously there is a voltage drop problem and that problem is between the fuse and the relay, in this case, the diode. Love the work Will, keep it up.

Excellent video! Trying to learn electrical, and found this incredibly helpful. Thanx again

Thank you! So grateful you took the time to make this video

Excellent video!!! Now I will apply my new found knowledge and see if I can solve my DRL problem. Thank you so much!

Very informative tutorial...nicely done. Thanks for posting this.

thanks i appreciate the compliment,I love the challenge that comes with electrical troubleshooting, I like to think its one of my specialty's, i enjoy it... so as long as you guys enjoy the vids i will continue, thanks again

Man that's a huge compliment thank you, i appreciate that

excellent information, I have a 2011 GMC Sierra, and will remember this video if/when my daytime running lights are problematic...thank you...

Thank you, Im glad this came along and was able to demonstrate

Your welcome, glad i could help its comments like this that keep me motivated :) Hope you enjoyed part 2

Superior knowledge of the vehicle´s circuits only comes from a full understanding of electricity, and that´s what I found in your video. Thanks

Thank you for your clear explanation. I learned a lot.

Awesome video and really like the electrical explanation.

Thank you for the compliment and the feed back its greatly appreciated

Great video! I can't wait for the next one.

You did a great job on Shan how to repair them lights very nice

Thanks for this educational vid, looking forward to seeing a follow-up

GREAT video. I have a problem with dim lights at night but haven't started diagnostics yet. This video gave me a lot of info that I'm sure will be useful if my DRL goes out. Sure would like to see a video on diagnostics of dim HB & LB lights at night. My truck is a 1998 GMC Sierra but I've seen a lot of GMC/Chevy trucks running down the road at night with lights that so dim I'm sure they are like me......LOOK out for that deer!!!!!!

Excellent video very well explained thank you!

Excellent work expert. Thanks so much. Waiting for part 2 please.

Thanks! Just what I was looking for. !!

Very informative video...waiting for part 2

Awesome video. Really hard to find anything about mid ninety's chevy DRL diag. Which is odd because there are usually several choices to pick from with a OBS

Very good explanation. TY sir.

I did not think this would help me until I got to the part where you describe the Diode. Then it hit me!!! The 2002 Chev ZR2 Tracker Diagram I have from web shows a Diode!!! I could not make out the printed symbol (very small on screen and lettering tiny). Now I know. It has to be the Diode because the voltage issue is the same---reduced power. My problem is the interior lights have failed. Now all I have is the challenge of finding the Diode in the vehicle. Thanks much for the detail.

Great logical diagnostic routine.

Awesome video learned alot!

Thank you for good lesson and valuable information

Thank you so much for taking the time and effort to educate us luddites. No more changing parts and hoping! Couldn't be better.

Great tutorial on auto electric troubleshooting. Clear and simple, like everything should be. I have tried this website but have message as FORBIDDEN

your welcome, thanks for the compliment

great work very informative

Thank you, will be uploading soon

Quality information here, good to see. Keep up the good work brother!

Very good video!!! God bless.

excelent as always!!

Thanks for the PM, I'll have a look.

good vid and info as always.

I love this video and your direction on it. How you provide the wire diagram and explain what you're doing and thinking and following along with everything on the diagram.

Thanks for the schematic lesson. You saved me.

camera is great too, crystal CLEAR!

Thanks for that helpful video. I have 2000 Chevy impala and I don't know where to find the (DRL circuit) thanks a lot.

good work...im subscribing 👍🏻👍🏻

thank you, part 2 cumming shortly

I really enjoyed this video. You have explained everything very well for me to understand. I do not have the exact same problem, but I think it will help me solve my problem. I have one question: If the DRL Relay is not working could it disable Daytime Running Lamps & Low Beams? At the 3:40 mark in your video you said if the headlight switch is on that there is no need for the DRL Module to be working. From the wiring diagram the Lamp Feed travels to Head Lamp Dimmer Switch to the DRL Relay to the Low Beams. If the wires are good and no ground outs, are the two suspect faults the Head Lamp Dimmer Switch and the DRL Relay? Or just the Head Lamp Dimmer Switch? I have a '98 Chevy K1500 with no DRL or Low Beam. High Beams work. Checked fuse 4 & fuse 15. I'm checking the DRL Relay in the morning. I hope it is not the HLD switch. Relays are easy access to replace and less expensive. Thanks again for posting the video!

I'd like to see that device in action -- good idea. The only negative is the fact you need to be careful regarding what voltage gets sent where, though in this case the risks are small.

Thank you... will be uploading part 2 soon

So brilliant

You caught me thinking the question as to why you used a test light to check ground when you could have used a DVOM. Your next sentence showed the voltage drop under the load of your test light, and I felt a little sheepish. I probably would have missed that, and spent hours trying to figure it out. What's the point of that diode anyway?

Thank you very much very helpful

where u get your wire diagram

:) many many times this misleads people including myself... Most DC live testing I Perform with a test light (With a bulb) just for that reason. An LED test light would show ok and can mislead as well. i should state some circuits are sensitive, so care needs to be taking while using a test light. i should cover that in a future video ... not 100% certain, will look into it though thanks again always look forward to your feedback

Excellent videos! Your editing is amazing - introducing the pertinent insets when needed! Your discussions are clear, logical and make total sense! I think most struggle with electrical, but your videos will give viewers a "fighting chance." Let's all guess on the clunking noise - ball joints and idler arm? LOL!

Good job !!

Thank you

Great video. I am curious what the symptoms were that turned out to be a faulty diode? What was not working properly on the truck before the resolution? On my suburban, the daytime headlights work fine during the day. At night when I turn on the light switch, the instrument lights do not turn on, nor to the rear running lights. Weeks ago I checked fuse 15, but until I watched your video, I did not know to also check fuse, which I will do asap. Based on my symptoms do you suspect the DRL circuit ... If not, what should I check first, the diode? Your video is one of the best I have seen. Thanks so much.

Installed sylvania leds and new sockets in my 02 suburban, having trouble "seeing" then light as the parking brake kills them. Idea to just set car up so they light/or not? THX

Hello..thanks for your detailed video here but I am a bit slow with electronics..I have a 93 suburban and am removing the OWL headlights and replacing them with old school round headlights..I don't want the daytime lights..hpw can I wire it so that just the parking lights come on when I flip the top rocker switch...also there is already a problem because sometimes the DRL and parking lights do not even work..I think it's in the switch because if I turn them off and on they will work again...thanks again

best diagnostic video ever how do you get the wire schematic to highlight, some sort of program?

Nice job

Hey I really like your videos I have a 1998 GMC Sierra having problems with a headlights when I click the high beams on no lights coming on but relay down on the floor next to the turn signal flasher relay buzzes

old video but really good one . recently i had one light burn out and so i decided to replace both DTL sockets and i did and know i have no power to either socket . i thought i soldered the wire reversed . DTL fuse under hood checked out good . not sure how i lost power

where do you get your interactive wire diagrams?

Thanks! Is there an online site with all makes and models that you use for the interactive wiring diagram as seen in this video?

I am installing roof top amber running lights and wanted to hook into the day time running system (fuse 4). Where would be the best spot to hook into it

great job i have a truck 96 gmc i just put a head light swicth in now i dont have running lights or brake lights n blinkers in the back of truck but have power to the harness i cheak the fuses all good n the bulbs r good im lost now

What computer program highlights the wires on the wiring diagram for you when you scroll over it?

rtoledo2002 Exactly! Problem solving as a general skill is not common knowledge to most. And it is not being taught to the public in any significant magnitude that I am aware of! You just don’t know how much you don’t know, so understanding that is critical. A drawing or other technical document gets you closer to a solution. Even if you don’t understand what something is or what it does, at least you know now those things are present and should be tested or accounted for. There is much freedom to be found with the recognition of “I don’t know” if answers/information is then sought out. This builds confidence and self worth/value and empowers the individual to grow more... ♾💡🌈

Your welcome

Very very good demonstration. I have been struggling with this very problem on my 2000 Sierra 1500. It started as intermittent but is now chronic. What schematic software are you using? And how can the Ambient Light Sensor be tested ?

Great video Ty I have a2003 Chevy Tahoe and one day the parking lights came on by themselves and I can’t turn them off in less pull the fuses for the taillights or unhook the ground on the battery would you have any idea what might cause this? Thank you in advance.

Awesome

What module was that you disconnected to get rid of the noise with the key in the ign?

Did you make the part 2 video? I am trying to locate the module.

where did you locate your schematic sheets at. Thanks

Saturday eve and I have nothing better to do:(;( But looking at your upload made my day.You are awesome.BTW where did you get that fancy test light?:):) Gan not wait for P2. Thank you

I'm checking fuses . I see what you mean with the numbers. Fuses good , my hdlp- hi is out. Lights in front but not in rear . Daytime running lights

Thanks I wanted to turn lights off when starting the truck

hi i have a question, it is on 2004 sub my head lights are on all the time and the driver side running lights the passager side is not the amber light on the passager side worked till pulled the bulb out i put a new one in still does not work thanks