QuestionDriver's side (only) ventilation on my 2004 Yukon XL Denali with 70K miles shifts over to very hot air several times a day, regardless if system is set for a/c or just vent. System resets only if truck is restarted.
Same vehicle now has a variable gas gauge that drifts to zero, chimes the low range bell, and then rises back up and then falls down again. Restarting the vehicle does not reset the gas gauge. Topping off the tank sometimes gets the needle to full and sometimes only to 3/4 full.
Dealer could not reproduce air symptoms and asked me to return when the air is blowing hot for diagnosis.
My other mechanic talked with GM and a Chevy dealer and suspects the body computer needs replacement/reprogramming and/or an a/c control unit problem.
Would appreciate advice and approximate cost to expect.
AnswerHi
I think you have 2 seperate issues.
1) The fuel level is PROBABALLY the Fuel level sensor, located inside the tank.
Cost would be APPROX. $125 for part and 3-4 hrs labor at your local areas rate.
2) The HVAC issue can be a few things.
I have seen this issue MANY TIMES and the problems are either
A)The wire chaffing below the glove box along the metal dash frame.
B) The Wire junction block on the passenger side, MAY have a loose terminals in connectors C4, C5, and C8. Have them look for poor terminal tension, backed out terminals or connectors not fully seated.
C)The Drivers side Temp door actuator is faulty. It is located under dash in center.
You can have the HVAC system scanned for codes. These codes will aid in diagnosis. I would HIGHLY suspect B or C as your problem.
Depending on final diagnosis
B = should cost labor only
C = $100 part and 1.5 to 2 hrs. labor.
I Hope this helps.
Good luck
Pawl
