headlight problem
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headlight problem
im new here i hope someone can help me on here. heres what i got the head lights not working .i replaced the dimmer switch and headlight switch and bulbs all new no junk yard parts. still no lights. i took lights out and bulbs out took a meter and the h/l plug has power with meter still hooked up i plug in bulb power go out. i ran wire from ground to plug to see if a week ground bad same thing happened no power so i ran a hot to plug and it worked light lit up. so i guess it has a good ground it losing the hot side. dont know what else to do, if u hold dimmer back lights work,if the truck sits with no bulbs in sometimes later u can put bulb back in and it work for a min then out again please i need help thanks
Fleet Mechanic
Joined: Jul 2010
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From: Winnipeg
Do you have Auto Headlights with or without Daytime Running Lights? or Do you have regular Headlights with or without DRL?
Check battery junction box fuses 3 and 9 Regular + 6 if Autolamp.
Check central junction box fuses 16, 28, 26, 27 Regular + 24 if Autolamp.
Check battery junction box fuses 3 and 9 Regular + 6 if Autolamp.
Check central junction box fuses 16, 28, 26, 27 Regular + 24 if Autolamp.
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Fleet Mechanic
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From: Winnipeg
There is a headlight and fog light relay in "aux relay box #3" behind center of dash. I believe if you remove that long oval panel on top of the dash it's in that area. There's also the auto-lamp sensor that's involved in the circuit on top of the right side of dash.
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You cannot measure voltage 'reliably' in these circuits wirh a meter because the meter does not put a load high enough.
The meter can see voltage through a high resistance but a normal load will drop the voltage to nothing across the high resistance fooling you.
The headlites come through a relay so all the functions can be controlled.
High beam ,low beam, flash, DRL and auto lamp functions.
If the flash works the light circuits are good.
It has to be behind that point.
You need the circuit layout to see the paths for each function and determine which path is in trouble..
Good luck.
The meter can see voltage through a high resistance but a normal load will drop the voltage to nothing across the high resistance fooling you.
The headlites come through a relay so all the functions can be controlled.
High beam ,low beam, flash, DRL and auto lamp functions.
If the flash works the light circuits are good.
It has to be behind that point.
You need the circuit layout to see the paths for each function and determine which path is in trouble..
Good luck.
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