QuestionQUESTION: 1) The ac blower often will go at the indicated speed on the speed lever on the dash, but will occasionally and apparently randomly turn off and then a few km/s later will turn on again at the previous speed (e.g. the switch is on high, the blower goes full blast, then off, then on) Sometimes flipping the speed switch rapidly left and right fixes it, sometimes not.
2) Related to 1), you have the air (heated or cool) blowing through the dash vents, then it decides to blow the air out the floor or decides to defog the windshield, and then if one is patient enough it goes back to vent later on. Sometimes moving the lever to bi-level ac or max ac and then back to vent gets it back to blowing the air through the dash vents.
I've wondered if these two issues were related to changes in transmission gears because the problems are lessened when driving in cruise control on a level stretch of highway.
What's up, any ideas?
ANSWER: John,
Nothing inside the a/c system is connected to the transmission other than (dependant upon make and model, I don't know what vehicle we are talking about here) through the PCM (computer)
I believe that under further investigation, you will find either a loose connector in the back of your control head or inside the control head itself.
Why I say this...
It will shut off, and you can turn it back on by means of flipping the switch. This leads me to the connections inside your control head. Another thig that leads me to this is you said it doesn't do it nearly as badly on a level stretch in cruise control. When your vehicle shifts gears, it creates a slight "jerk" that jerk may be all it takes to break connection and stop power from flowing to your fan. As it settles back, or gets jerked again, the connection is remade and it works.
I also believe that it is in your control head becasue this is the only component that connects your door actuators on the ventilation system and the fan.
Thank you for the question, I hope I was of some assistance. If so, please remember to rate this answer. If I can do anything further during this process or in the future, do not hesitate to ask. Thank you again and good luck in everything.
---------- FOLLOW-UP ----------
QUESTION: I apologize, I drive a 91 Safari van. I guess getting at the control head requires removing the dash?
AnswerJohn,
You shouldn't need to remove the dashboard. If you remove the trim from the center panel, you will see the 3 or 4 screws that mount it to the dash. Remove these and it will come right out. The hardest part of the job is to remove the trim. Be careful so as not to snap any of the plastic clips that hold it in.
By control head, I am referring to the device in which you manually control the operaton of the A/C. In case I was vague and had you thinking it was another piece that was hidden away.
Thank you for the question, I hope I was of some assistance. If I can do anything further during this process, or in the future, please do not hesitate to ask. If you found this response to be of some assistance, please remember to rate this answer. Thanks again and good luck in everything.
