20 Most Recent 1995 GMC Yukon - Page 9 Questions & Answers

I can't find any old service bulletins related to the hvac on the 95 yukon.
If you can send me a post or comment, telling me what problem or problems the panel is causing. ie. no hot air/warm only/cold only/blower
only works on hi/only on low/not at all/no air to def/to floor etc.
And what if any tests you've already done, that lead you to the control
panel. I have the schematics and component diagrams in front of me.
So if you can send me that information, we can try to resolve this issue.
Thanks

todytwo

THE VACUUM LINE SHOULD CONNECT ON THE BACK OF THE INTAKE ON THE DRIVER SIDE NEAR MIDDLE. START TRUCK AND FEEL AND LISTEN FOR LEAK.

THE DIOED IN THE FAN SWITCH IS GONE. CHECK VACUUM LINES IN ENGINE BAY FOR LEAKS OR BROKEN CONNECTIONS ON PASSENGER SIDE, THEY FEED ACTUATORS UNDER DASH THAT CONTROL HEATER FUNCTIONS.OR A VACUUM ACTUATOR COULD HAVE FAILED.

CHECK TO SEE IF YOUR GETTING 12VOLTS TO THE POWER CONNECT UNDER THE SEAT WITH THE KEY ON WITH A TEST LIGHT OR VOLT METER . CHECK FUSES,TRY RUNNING A WIRE FROM A 12 VOLT SOURCE TO SEAT POWER CONNECT, IF THAT DOSEN'T WORK SEAT MOTOR COULD BE FAILING

Sounds like it could be a torque converter problem. Yours is an electronic 700r4. Take this to a reputable transmission shop for repairs. There are a multitude of problems associated with the symptoms you describe.

FOR THE YUKON FAMILY THE BLOWER MOTER IS ON THE RIGHT SIDE OF THE CAB PULL BACK THE PLASTIC COVER OR CUT IT OFF REMOVE THE 3 OR 4 SCREWS THAT HOLD IT IN PLACE CUT THE WIRE TO IT AND THEN REMOVE IT THE NEW BLOWER WILL HAVE TO BE WIRE TO THE WIRE THAT YOU CUT AND THEN SCREW THE BOLTS BACK AND YOU ARE DONE .........

On the full size, the front actuator is electric, not vacuum.

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.

If I were you, I would buy a new heated actuator. They are available at most auto parts stores, and are about $90. They are also on eBay for about $55 plus shipping. These are very easy to change - just thread out the old one, and thread in a new one.

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.

check all of fuses and relays first. the fan motors burn up. replace the fan motor

Fig. 28: 1995-98 GM Truck Chassis Schematic...



Fig. 29: 1994-98 GM Truck Chassis Schematic



For more details, I suggest visit autozone.com (free register) and select the year, brand and model for acceso to the repair guide; check the Chassis Electrical>> Wiring Diagrams

Hope helps.

that is not a code,that is a technical service bulletin that tells how to fix a certain problem

A "rod knock" is the sound made by a bent pushrod. This is a MAJOR problem and will lead to a blown engine if not repaired soon. Take it to a reputable mechanic immediately. Be prepared to pay a substantian amount of money for the repairs. Good Luck.

Hello,
This problem may be very easy to fix. It may be your belt on the motor, could be the alternator belt, main serpentine belt etc. Check all your belts, you should only have about an inch of play in all the belts, any more than that the belt will slip across the pulleys causing them the squeal.
If it is the water pump bearing, check and see if your fan that is mounted to the water pump is loose, or moving all over the place. You will see the pulley that the fan is mounted to moving likes its about to fall off. In that case you will need a new water pump. Hope this helps!
-Steve

HI there
I have read your report. The way you describe it sounds like your rod is knocking. If you every driver down the road and feel that gas peddle starts to vibrate then you fixing to blow a rod. sometimes the blow form the side of the motor and others blows straight down through the oil pan. just to let you. be careful and hope this info gets you on the right track.
thank you for writing to fix ya.
Best Regards Richard

you will need to put a pressure gauge right on the engine to see whats real. Do an oil service with filter. This could help, If the pressure is stll low you could put a oil pump in and hope for the best. As long as you have pressure you should be ok. 20psi at idle can be a sign of old oil so cross your fingers.

your emission label undr the hood tells you. 44thous

BINGO ! ! The fuel indicator mechanism is IN the fuel pump assembly (in the gas tank). Apparently the mechanic that did the work did NOT hook up the wiring harness OR the float is jammed. Go back to who ever did the work and COMPLAIN.

we can guess or a shop can tell you for sure. It may be a wheel sensor.

If your a smoker the ashes destroy the contacts on the clockspring on the steering coloum. also these wear out in time normally.

the H.E.I distributors have a problem with the modules blowing . check you have power in the main power wire to the dist with key on if there is then my guess the module blew / pop the cap off the dist ,remove the rotor , you'll see a half moon looking flat electric box with 2 wires going in ea side change that part and try it there's also a pickup coil /if you can make sure no wires are broken on the pickup coil or change it .hope that helps . sounds like you lost spark and that would be my first guess / the module went :)

you may have a bad oil filter, the best check is to install an oilpressure guage to find out what the actual pressure is, or maybe you put in too light an an oil,

the pressure switch is loctated on top of the oil filter housing, should be a round metal cylinder style with oen wire going to it, left side of motor right next to tranny