another Headlight question - The 1947 - Present Chevrolet & GMC Truck Message Board Network

manimal · 03-18-2021, 02:13 PM

I have a 2000 (GMT400 body) C2500. I am having issues with the healights. Specifically the low beams. I have DRL's (working) and high beams, NO LOW BEAMS. I have changed the multi function switch(turn signals switch) the brake light switch, and the headlight switch, still no low beam lights. I have removed the #15 fuse, still no low beams. New bulbs too. Now because the DRL's are working, that tells me that it's not a wiring issue because they are on with DRLs. High beams work just fine. What am I missing?
Thank You
Lance

sntrym95 · 03-18-2021, 02:47 PM

Have you checked the relay in the fuse box under the hood?

manimal · 03-18-2021, 11:38 PM

Relay? I know of the maxi fuse. Unless my power distribution box lid has been changed.

sntrym95 · 03-19-2021, 09:11 AM

On the 2000 1500, there is a headlamp relay in the underhod fuse box. Being that you have a 2500, I'm not sure which fuse box they used, so there might be one in the underhood fuse box. If it's the older fuse box like the 88-98, then it won't have one and all the voltage runs through the switch and the breaker in the inside fuse panel.

So if you have the old fuse box, check the breaker in the panel on the drivers side of the dash

manimal · 03-21-2021, 11:59 PM

changed the relay under the dash by the e-brake pedal, still no low beams.

Just call me Sean · 03-22-2021, 12:19 AM

Do the high beams turn off when the low beams are selected? Have you checked for power out of the switch for the low beam signal?

manimal · 03-23-2021, 02:50 PM

Yes, the highs go off when I switch to lows. have not checked signal from switch on lows. I did just replace the switch, the multi function switch and the brake light switch and bulbs.

manimal · 03-29-2021, 11:46 AM

Ok, so this weekend I tested the pins for the relay. Pin 86 (ground) is bad. Not grounding. I have tested a known good power source then grounded the pin and nothing. I have seen a few different wiring diagrams, but not sure which one is correct. WHERE is the DRL module? or IS there one? I found the diode, but is there a module?

Just call me Sean · 03-29-2021, 12:42 PM

Mine is in my glove box.

It's under the dashboard to the left of the ash tray.

Just call me Sean · 03-29-2021, 08:32 PM

This is the module. My headlights work normal without it. Never tried putting it in, it was like that when I got it.

manimal · 03-29-2021, 10:08 PM

Thats the diode right? Mine is fine. My concern is pin 86 at the convenience center for the drl.relay is not grounding.

Just call me Sean · 03-29-2021, 10:28 PM

Whatever it is, it isn't necessary for the headlights to work with the switch.

71gmcC15 · 03-30-2021, 01:25 PM

Quote:

Originally Posted by Just call me Sean

This is the module. My headlights work normal without it. Never tried putting it in, it was like that when I got it.

I've ripped that stupid th im ng lout of every 95 up obs me and my friend had. Hate drls.

manimal · 03-31-2021, 08:18 PM

I kinda feel stupid. I replaced the relay with a new one from the parts store, same as the one I took out. Well it turned out it was the wrong relay to begin with. I pulled the relay from my 99 Suburban and.....Headlights now WORK. Difference? the one I pulled and replaced in the truck was a 4 blade relay, the one from the Suburban is a '5' blade.
So, Thank you to all that helped me.
Lance

03-18-2021, 02:47 PM	#2
sntrym95 Registered User Join Date: Jan 2006 Location: Big Pine Key, FL Posts: 745	Re: another Headlight question Have you checked the relay in the fuse box under the hood? __________________ Mike

03-18-2021, 11:38 PM	#3
manimal Registered User Join Date: Oct 2006 Location: Southern Kalifornia Posts: 3,066	Re: another Headlight question Relay? I know of the maxi fuse. Unless my power distribution box lid has been changed. __________________ ------------------------------------------------------ -Lance 2000 Chevy C2500, 5.7, 4L80e 1999 Suburban K2500, 7.4, 4L80e 1980 Camaro..son's car...PROJECT

03-19-2021, 09:11 AM	#4
sntrym95 Registered User Join Date: Jan 2006 Location: Big Pine Key, FL Posts: 745	Re: another Headlight question On the 2000 1500, there is a headlamp relay in the underhod fuse box. Being that you have a 2500, I'm not sure which fuse box they used, so there might be one in the underhood fuse box. If it's the older fuse box like the 88-98, then it won't have one and all the voltage runs through the switch and the breaker in the inside fuse panel. So if you have the old fuse box, check the breaker in the panel on the drivers side of the dash __________________ Mike

03-21-2021, 11:59 PM	#5
manimal Registered User Join Date: Oct 2006 Location: Southern Kalifornia Posts: 3,066	Re: another Headlight question changed the relay under the dash by the e-brake pedal, still no low beams. __________________ ------------------------------------------------------ -Lance 2000 Chevy C2500, 5.7, 4L80e 1999 Suburban K2500, 7.4, 4L80e 1980 Camaro..son's car...PROJECT

03-23-2021, 02:50 PM	#7
manimal Registered User Join Date: Oct 2006 Location: Southern Kalifornia Posts: 3,066	Re: another Headlight question Yes, the highs go off when I switch to lows. have not checked signal from switch on lows. I did just replace the switch, the multi function switch and the brake light switch and bulbs. __________________ ------------------------------------------------------ -Lance 2000 Chevy C2500, 5.7, 4L80e 1999 Suburban K2500, 7.4, 4L80e 1980 Camaro..son's car...PROJECT

03-18-2021, 02:13 PM	#1
manimal Registered User Join Date: Oct 2006 Location: Southern Kalifornia Posts: 3,066	another Headlight question...FIXED I have a 2000 (GMT400 body) C2500. I am having issues with the healights. Specifically the low beams. I have DRL's (working) and high beams, NO LOW BEAMS. I have changed the multi function switch(turn signals switch) the brake light switch, and the headlight switch, still no low beam lights. I have removed the #15 fuse, still no low beams. New bulbs too. Now because the DRL's are working, that tells me that it's not a wiring issue because they are on with DRLs. High beams work just fine. What am I missing? Thank You Lance __________________ ------------------------------------------------------ -Lance 2000 Chevy C2500, 5.7, 4L80e 1999 Suburban K2500, 7.4, 4L80e 1980 Camaro..son's car...PROJECT Last edited by manimal; 03-31-2021 at 08:15 PM.

03-29-2021, 11:46 AM	#8
manimal Registered User Join Date: Oct 2006 Location: Southern Kalifornia Posts: 3,066	Re: another Headlight question Ok, so this weekend I tested the pins for the relay. Pin 86 (ground) is bad. Not grounding. I have tested a known good power source then grounded the pin and nothing. I have seen a few different wiring diagrams, but not sure which one is correct. WHERE is the DRL module? or IS there one? I found the diode, but is there a module? __________________ ------------------------------------------------------ -Lance 2000 Chevy C2500, 5.7, 4L80e 1999 Suburban K2500, 7.4, 4L80e 1980 Camaro..son's car...PROJECT

03-29-2021, 10:08 PM	#11
manimal Registered User Join Date: Oct 2006 Location: Southern Kalifornia Posts: 3,066	Re: another Headlight question Thats the diode right? Mine is fine. My concern is pin 86 at the convenience center for the drl.relay is not grounding. __________________ ------------------------------------------------------ -Lance 2000 Chevy C2500, 5.7, 4L80e 1999 Suburban K2500, 7.4, 4L80e 1980 Camaro..son's car...PROJECT

03-31-2021, 08:18 PM	#14
manimal Registered User Join Date: Oct 2006 Location: Southern Kalifornia Posts: 3,066	Re: another Headlight question I kinda feel stupid. I replaced the relay with a new one from the parts store, same as the one I took out. Well it turned out it was the wrong relay to begin with. I pulled the relay from my 99 Suburban and.....Headlights now WORK. Difference? the one I pulled and replaced in the truck was a 4 blade relay, the one from the Suburban is a '5' blade. So, Thank you to all that helped me. Lance __________________ ------------------------------------------------------ -Lance 2000 Chevy C2500, 5.7, 4L80e 1999 Suburban K2500, 7.4, 4L80e 1980 Camaro..son's car...PROJECT



Register or Log In To remove these advertisements.

Register or Log In To remove these advertisements.