What’s going on guys i’ve got here a gmc sierra 1500 and i’m using this truck to point out to you the location of the headlight fuses the relays for the headlights uh your fog light fuses and relays as well as your daytime running lights your high beams your low beams all of that can be found underneath this cover here so we’re going to remove this by just pulling
Up and setting this cover aside i’ll start with the relays so we’ve got a fog light relay right here we’ve got a low beam relay here this is your high beam relay and this is the relay for your daytime running lights now my favorite way to troubleshoot relays is by tapping on them so let’s say my high beam relays don’t turn on what i’ll do is i’ll turn on the high
Beams and i’ll come here and i’ll tap on that relay and see if it makes my high beams start working sometimes relays can get stuck and by tapping on the relay or wiggling the relay you can temporarily cause it to work again another troubleshooting step you can do is you can remove the relay and you can swap in a different one so let’s say my high beams do not
Work but my fog lights do i’ll take the fog light relay because i know that one works and i’ll put it in the position of the high beam if now my high beams start to work then i know that the original relay here is probably no good now of course we’ve got to have working fuses as well so i’ll go over the fuses in detail the fog light fuse is going to be powered by
That 15 amp fuse right there that i’ve covered in red paint and that fuse should be receiving constant power the daytime running light fuse is right next to the daytime running light relay and again it’s the one that i’ve got the red paint on now the low beam and the high beam fuses are a little different in that they do not receive constant power they are only
Energized when the relay is working so what’s cool about that is you can check to see if you’re getting voltage on those fuses and that will let you know if the relay is being triggered or not so we’ve got the high beam and the low beams here so these four 10 amp fuses here this is for the driver side high beam that is for the passenger side high beam this is
For the driver’s side low beam and again that is for the passenger side low beam and if you look at the exposed metal on these fuses that’s where you can check to see if you’re receiving voltage and as far as removing the fuse it’s real simple you know you just use needle nose and they’ll come right out and that’s what a good fuse looks like there now further
Troubleshooting what we can do is we can manually provide power to any of these circuits so again i’ll use the high beam as an example i’ve removed the high beam relay and if i use a paper clip or a wire to connect these two pins together that will result in power being sent directly to my high beam bulbs so if i connect these two and my high beams do not turn
On then i know that the bulbs themselves are bad or i might have a bad connection somewhere you can do that with any of these relays actually so it’s all it’s the same two relays so it’s the diagonal so i’ll just go and remove here’s the daytime running light i’ve got it color-coded in red there my low beams so all of these circuits can be tested in the same
Way by connecting these two pins together so yeah i hope this information was helpful for you and a good starting point in troubleshooting the lights on your gmc sierra please let me know if you have any questions or also if you have any advice thanks for watching
Transcribed from video
2004 GMC Sierra 1500 Headlight Fuses & Relays, Fog Light Fuse & Relay By Lehew Tech
