2002 Yukon denali headlights not work....all otherlights and signals work fine, it is not the headlight switch or the switch on the column any ideas?????

If front park lights are working highly unlikely headlight switch is the issue. Is the vehicle equipped with a trailer towing package and wiring to the rear? I would start there. This vehicle may also have a taillight module located under the vehicle on the passenger rear attached in the wheel well area that goes bad

They have fuses these days, check them.

Also check to make sure the fuses get power with them turned on or the switch could be bad................... but I have seen two bulbs go gad at the same time.

sound like battery has weak or battery terminals and post need cleaning. have battery charged and checked, if battery good. alternator not charging battery. if battery over 5 years old more likely battery is bad.if battery too weak head lights wont turn on battery dead this time of year if battery old. cold weather will finish it out.

i would try replacing those bulbs,the headlights are dual filiment and can work on just high beam and not on low beam,so start there and replace your bulbs

time for a new headlight switch

check the head light relay int he engine compartment and the fuse to, if both these are OK then the switch is defective, the switch draws high amperage when operating the fog lamps and head lights. Buy the GM or Del-co switch. you can go to this web site to get recall info on this car as well they list parts prices as well.
http://shop.advanceautoparts.com/webapp/wcs/stores/servlet/subcategory_Lighting_-49997541_-49997588_10151_10051_-1___#storeId=10151&langId=-1&catalogId=10051&categoryId=-49997541&searchTerm=&pageId=ajaxPartList&category=&keywords=Lighting&l1_categoryId=&l2_categoryId=-49997588*-49997541&partType=&facetFields=mfrName_exact%2CpriceBucket%2Cclearance%2Csale%2C&beginIndex=0&filterValue=part_type%3A%22Accessories*Lighting*Driving+Light+-+Universal%22%7CAccessories*Lighting*Driving+Light+-+Universal&sortBy=0&pageSize=20&filters=part_type%3AAccessories*Lighting*Driving+Light+-+Universal

Hi,
The simple answer may be that the low beam side is burnt out. Replace the bulb.
However, if both headlights have stopped working when switching to low beams, there may be a problem with the relay or the switch itself. If the cost of a relay is low for your car, it may be less expensive to simply replace that component than to have it diagnosed in a repair shop. Replacement of the switch requires some disassembly of the steering column or dash in most vehicles.
This is how to fix the low beam..
1.Check your fuses. The plastic panel covering the fuses should have a diagram detailing what each fuse covers. If yours is missing, or unlabeled, check your owner's manual, or a Hanes(tm) or Chilton(tm) repair manual. Often if a headlight is not working, it is the result of a blown fuse. Fuses have a wire running through them that will melt when too much current is run through them. If the fuse is blown, the wire will be broken. If the fuse for the headlight you are working on has an intact wire, it is likely the problem lies elsewhere.
2.Swap the headlight for its twin. If your left headlight does not work, put the light from your right headlight in its place. If it works with the other headlight in place, your headlight bulb is dead, and needs to be replaced.
3.If this does not work, try using a voltmeter on the plug for the bad headlight. Turn on the ignition, and turn the headlight switch. If the voltmeter shows no current, then either your switch or the wiring leading to the headlight has gone bad.
4.If replacing your headlight switch does not solve the problem, then there is a break in the wiring leading to the headlight, and the wiring will need to be replaced.
Thanks for contacting fixya.com

Ok Guys Thanks I will check into the dimer switch first, But if it is the turn signal switch assembly with the high beam control on it, it will not be cheap, I think they run about 260.00 each.

Thank you for your input.

FROM LUSTY KID:

Check your bulbs first, I have lost both headlights on my ford at once on account of the bulbs burning out at the same time. Same thing probably happen, you have one filament out. The lights can work, but if the filament for brake is burnt, you don't see brake lights.

As for the cruise control. Check fuse box first. If OK check vacuum hose to actuator in engine compartment for starters.
Advise:

Check the headlight fuses in the engine fuse box compartment. Not sure if the lights have relays, but they will be clearly mark in the inside of the top cover for location.