Blower Resister?

[itbejared]

ok, blower is working fine under normal conditions a/c and heater, until heavy acceleration then no air is coming from the vents yet you can still hear the blower going.. i have done a search and I think its the blower resister under the hood? would I be right with the educated guess?

thanks for the replies guys..

 

[sailorman3]

blower resister

Usually if that resistor is gone only high fan speed will work. What happens is that for slower fan speeds the switch puts in more resistance to drop the voltage, thus making the fan go slower. If all resistors are open, fan only goes on high speed.
Sailorman 3

 

[itbejared]

ok.. so then any ideas why i would lose all air flow under accelleration? rear blower works perfectly fine.

 

[Maniak]

If I remember correctly (from the symptom and what I've seen on here) you have a vacuum check valve problem.

When you get on the throttle (heavy acceleration) the vacuum changes which then moves what I believe is called the blend door.

When this door moves the air goes out the defrost vent instead of the a/c vent.

I hope I pointed you in the right direction.. and I'm sure someone else on here will have some more precise instructions...

~Mark

 

[itbejared]

now that making a little more sense.. I have been w/o AC for some time due to a broken blend door.. but it was stuck in the heat position so I didn't mind.. but then this started happening... I just did a "temp" fix on the blend door so that I am getting heat and AC now.. I will check on the drive home from work to see if its blowing out of the defrost vents once i hope onto the freeway.

thanks for giving me some direction.

 

[itbejared]

ok... you were correct, when under heavy acceleration the air is coming from the defrost vents and not from the AC vents. So that makes sense thats it's a vacuum leak somewhere. So now the question being........ where in the world do I look and where do I go to fix?

 

[Opera House]

Not so much a leak, but the check valve is probably stuck open. Should be located somewhere between the vacuum manifold and the plastic air tank. The vacuum in the tank leaks back to the manifold under acceleration.