Wiper arm removal 1999 yukon denali

Check your fuses.

Do your windshield wipers also stop working? If so, the most likely cause is your Body Control Module (BCM). The 1999-2000 GMC Denali was known for having issues with the retained accessory power relay solder connection inside the BCM. If you're up to the task of removing the BCM (located inside the center console- kind of a pain to get at) and know how to solder, you can fix it. Otherwise the BCM will have to be replaced.

I had the same problem with mine and it was the body control module kinda. If you take the cover off of you center console, the bcm is back towards your cd changer. It is all the way at the bottom and has a 15+ wire wiring harness pluged into it. The problem with mine was simply the plug was coming lose. Hope this helps and is a simple fix for you too.

Windshield Wiper Motor
Removal & Installation
To Remove:

1. Remove wiper arms.
   
2. Remove weatherstrip from cowl.
   
3. Remove two cowl vent grille panel screws.
   
4. Remove windshield nozzles and hoses.
   
5. Remove three cowl vent grille panels.
   
6. Disconnect windshield wiper motor electrical connector.
   NOTE: Do not remove crank arm from windshield wiper motor.
   
   
7. Loosen nuts that attach the drive link brackets to the crank arm.
   
8. Remove wiper motor crank arm brackets.
   
   
   
   
   
   
   
   
   
   
   
9. Remove three bolts and windshield wiper motor from vehicle.

To Install:

1. Install windshield wiper motor and three bolts.
   
   
   
   • Torque to: 62 in lbs. (7 Nm)
   
   
2. With right side linkage closest to the windshield wiper motor, install drive
   link brackets to wiper motor crank arm.
   
   
   
   • Torque nuts to: 44 in lbs. (5 Nm)
   
   
3. Connect electrical connector.
   
4. Install nozzles and windshield washer hoses to cowl vent grille.
   
5. Install three cowl vent grille panels and screws to vehicle.
   
6. Install weatherstrip to cowl.
   
7. Install wiper arms.

Ck your fuses

PROBLEMS IN THE WIPER MOTOR MODULE.

Do you mean the wiper blade or the wiper arm?

The wiper blade should have a small tab or lever on the underside of the hinge where it attaches to the arm. Use a small screwdriver or a pick (etc..) to gently pry the lever upwards to pull the locking tab out of its corresponding hole on the wiper arm. Once the tab is up, firmly grasp the wiper blade and pull towards the base of the wiper arm. Sometimes they stick a little, just be careful not to bend the wiper arm.
If you are looking to remove the wiper arm, remove the plastic cap at the base of the wiper arm to gain access to the nut below. Using either a 13mm (1/2 inch) or 15mm socket (depending on the model) remove the nut by turning counter-clockwise. Once the nut is off, place your hand in the middle portion of the wiper arm and firmly push downward, being careful not to bend the arm. What you are trying to do is rock the arm off of the wiper motor stud. Be sure to mark where the wiper blade rests on the windshield before removing it, so you can reassemble it in the same spot when you put it back together. Use a grease pencil or something else that you can clean off later.
Hope this helps!

BINGO you need to flip the wiper arm end cover up or off and tighten the nut, 13mm usually

your wiper arm just needs to be tightened up

but align them or it as you tighten it

This is caused by a problem in the Body Control Module, have it tested for trouble codes.

We had the same problem and sometimes they wouldn't turn off. The intermittent wipers were random. We replaced the wiper motor. Be sure to get the motor with two balls on the wiper shaft (one for each wiper arm). If you can't find it, you'll have to change the part out on the new motor. Keep the wiper arms in the same location on removal, or it will jam and you'll have to start over.