20 Most Recent 1996 GMC Yukon - Page 4 Questions & Answers

check the switch under the brake pedal they uaselly stop working after a while and just buy another and put it on also check your fuses first and to see if u have any burnt out bulbs

Here's a link to the oil pan removal guide with pan bolt torque specs.

Fuse is located at the end of eh dash on drivers side and the Actuator is located at the front differential and on the passenger side.
When in 4wd mode, a switch on top of the transfer case conducts 12 volts out to the actuator. Wire #50 (brown) is the 12v feed, and it conducts to the light blue wire (#900) to the actuator.
When shifted out of 4wd, the switch opens up and no voltage goes to the actuator.

Check voltage at the connector for the front actuator (at the front differential - it looks like a large bullet that threads into the front diff.) If it has 12 volts, the actuator is the problem. If it does not have 12 volts, check the transfer case switch and the power feed to the transfer case.
I'll assume it is the actuator, if the plug to the actuator is getting 12 volts when in 4wd.
The way this actuator works, is it is a sealed chamber that gets heated by voltage. When it heats, the pin in the end swells and pushes a shift fork in the front differential. The shift fork engages a spline on the passenger side of the differential, and boom! you have 4WD.

GM offered an upgrade to this actuator that is a motor instead of a heated device. However, it requires a small harness addition, a spacer, and a new actuator. It is about a $150 to $200 option.

Good luck. The actuator is usually the problem 90% of time but recheck all of the wire harness just to maker sure there is no short before replacing any parts. The actuator may not be fully engaged or disengaged and the fork to the spline may be what is causing the grinding.

88-UP C/K ACTUATOR UPGRADE
VEHICLE SERVICED: 88-99 CHEVROLET FULL SIZE
PURPOSE: IMPROVE AXLE CONNECT ENGAGEMENT TIME AND
COMPONENT RELIABILITY.

SYMPTOMS: NO FRONT DRIVE AXLE ENGAGEMENT WHEN SHIFTED INTO 4X4.

Obtain the following GM part numbers:
(1) 26060073 Actuator
(1) 88959465 Harness/Spacer Kit

Are you saying the voltage at the battery posts is 9 or 10 volts with the cables removed ?Have you charged the battery with a charger ?

YOUR HEATER CORE IS STOPPED UP. YOU CAN TRY HAVING THE COOLING SYSTEM POWER FLUSHED. BUT I HAVE HAD LIMITED SUCCESS WITH THIS.THESE TRUCKS HAVE A PROBLEM WITH THE SYSTEMS CLOGGING. AFTER YOU HAVE IT FLUSHED DO NOT REFILL WITH DEXCOOL. THAT WAS ONE OF GM GREAT IDEARS THAT IS NOT GOOD THE STUFF IS CORRISER. REFILL WITH REGULER GOOD OLE GREEN ANTI FREEZE WITH A50/50 MIX HOPE THIS HELPS BILL

Is the dome button at the headlight switch turned on? little button down and to the left of the headlight switch.

I had a similar problem caused by humidity and a short in the distributor cap so replaced the distributor cap and rotor. Problem solved. Don't buy discount branded parts or you will have the same problem again in a few weeks. Really cheap price equals really cheap parts that will fail early.

Check to see if your "Dome Overide" is activated

You can put the shifter in 2, 3, or overdrive. It will still start in first and shift up to whatever gear you have selected. Try it, you wont damage anythingl

Heater core is leaking and needs to be either replaced or by-passed.

I would suggest replacing fuel filter and maybe having a pressure test on fuel system and if pressure is low this would indicate fuel pump is weak and may need to be replaced..hope this helps and Please rate my post and good luck.

The P0300 means Random/Multipe Cylinder Misfire Detected.----------Ktag K-TAG

ck crank sensor and ignition control module then distributor then pcm/ecm.

either your fuel filter by be plugged, could be injector shorting out could be throttle position sensor

Sounds almost too simple but have you checked the wiring to the parking brake. If it is depressed enough to light the brake light in the dash the DRL's will not light or if the wires are not hooked up same problem. You also state you have checked the control board under the dash I assume you are talking about the Diode an aluminium finned box a little bit larger than a deck of playing cards under the dash on the right side of the steering colum at the swell in the dash. remove this diode and insert a shunt in the connector and see if those babies light up if so its the diode

Usually a sign the system is low on freon or has an electrical problem.

Could be the blower motor or the resistor.A mechanic would check for voltage at the motor when it is not working.

Check the connectors to the AC blower motor switch and the motor itself, see if they are burnt/discolored, replace as needed. Also replace the blower motor. The repair connectors are available from the dealer.