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Headlights not working??
Roger Milne:
--- Quote from: Eric Maclean Co-Admin on October 15, 2025, 01:42:24 PM ---Roger
it is not uncommon to find the Day Time Running lights disconnected or deleted on a vehicle with LED headlight bulbs installed ,the reason is that the DRL systems usually feed both the high beam and low beam headlights through a resistor to achieve a dimmer out put as to not blind on coming traffic .
Unfortunately when LED headlight bulbs are installed they draw much less current than did the incandescent or halogen bulbs did ( which is a good thing )
But with the lower current draw the in line resistor in the DRL system no longer can create the volt drop required to cause the headlights to dim and in effect now both high and low beams are on at full intensity which creates a problem.
One would think you could install a larger resistor to cure the problem but one would be wrong as LED head light bulbs are not dimmable they have a working voltage of between 8 Volts and 18 Volts if you go below the 8 volts they simply shut off ( they are either off or they are on at full intensity).
This is why you will discover the Day Time Running lights have been disconnected.
Hope you find this helpful
Eric
--- End quote ---
Thanks for the input Eric, and you maybe be correct in assuming his attempt to delete the DRL part of the circuit from the plug to headlights. From everything I can assume at this point is he did just as you said with the DRL components, but sadly I inadvertently took out part of the Dim Headlight mod' and didn't realize this as I was deleting part of another one of his "upgrades" when he installed a LED light bar.
So I'm at the point in this troubleshooting of trying figure out where and what part of the mod is still in place and which part I've accidentally removed.
So as to not convolute your reply, I'll make a separate post reply explaining where I'm at and maybe someone can jump in with an idea as to my next step.
Roger Milne:
He guys, I really appreciate the tips and input. But to try and bring some of the ideas back full circle, I figured I'd leave it here as to what I've figured out and what is working and what is not.
So as it sits currently, I have NO Lo Beam. Only Hi beam. I have parking lights and turn signals.
I removed what I incorrectly thought was wiring for an LED light bar, which appears to have been piggy backed in conjunction with the "Dim Headlight Mod"
So, currently I have a Lo Beam wire that comes from the "smart wheel" that he had cut and spliced a feed to both left and right Low beam bulb connectors, ( this may have been feeding through the relays as part of the Mod', but can't recall now). This wire I cut out and put a connector terminal back on and reconnected both ends at the bulb connectors. When this wire is connected I blow Dimmer Fuse #69. When I disconnect it I don't blow the fuse, but ONLY get Hi Beam to work NO Lo Beam. I've attached a couple pics. First one is the wire I cut out from the So I'm guessing this is wire from the smart wheel. The others are the Dim light mod for reference. I believe I have the wires that where bridged from the original circuit to the new relays and somewhere there's another wire that is back feeding the low beam circuit because I removed the relays, but have't figured out where the other wire is yet that would put the circuit back to stock ( ie, not having the Mod in place)
Sorry if this seems like I'm going around and around, but I appreciate the help.
Steve Huber:
Roger,
Remove the headlight mod relays and see if F69 blows when low beam is selected. If it does, problem is between the F69 and the removed relay. If not, problem is between relay and headlights. Then I'd first try installing the high beam mod relay in place if the low beam one to verify the original relay isn't bad. If that's not it verify that pin 87 of the low beam relay is wired to VCB-11.
Steve
Roger Milne:
--- Quote from: Steve Huber on October 16, 2025, 02:54:59 PM ---Roger,
Remove the headlight mod relays and see if F69 blows when low beam is selected. If it does, problem is between the F69 and the removed relay. If not, problem is between relay and headlights. Then I'd first try installing the high beam mod relay in place if the low beam one to verify the original relay isn't bad. If that's not it verify that pin 87 of the low beam relay is wired to VCB-11.
Steve
--- End quote ---
Hey Steve.
I have inadvertently removed all the mod' and relays and ditched them. I now know that it appears the PO had done the mod' and I was unaware of it and assumed the relays were for the light bar. So the quick answer to your reply is YES when I select Lo Beam F69 blows. BUT only when I reconnect the wire that he spliced (which is the one in the picture in the previous post). So I'm heading down the path of it's not a relay issue( as they are both eliminated) but trying to reconnect the VCB-11 and VCB-12 back to original , if that makes sense.
Steve Huber:
OK.There should be nothing except the dimmer switch between pin 30 of the headlight relay (R11) and VCB-11 or 12 depending on whether you have high or low beam selected. To make troubleshooting easier consider pulling F69 and jumpering from the cold side of the fuse to the pin 30 slot of R11. You should have a short between F69 and VCB-11 or 12 depending on dimmer switch position. The resistance to ground should be the same in either dimmer switch position as you will (should) be measuring the headlight bulb (LED) resistance only.
Steve
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