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Topic: no air out the dash vents (Read 534 times) previous topic - next topic

no air out the dash vents

I've searched for a couple days and not found the topic so here goes, before I start taking stuff apart. The vacuum switches appear to be working, I can hear stuff moving about when i push buttons, The blower sounds like it wants to cooperate, but very very little air comes out the vents. I suspect dash AC is down for the count but is a separate issue and rght now defrost is more important. First thing I'll take apart is the blower box on the pax side nose unless someone here has a better plan. Hoses under the dash are intact and not much air is present at the distributer box. I hoped to see an air filter to replace but no luck as such...
Jay
1989 U280 SE, 36', 3208T Cat, build 3292

Re: no air out the dash vents

Reply #1 –
Jay,
In the heat or defrost modes is the air flow good (normal)?
Yes or no would tell the health of the blower motor.
If that is OK does the airflow stop at the heat and defrost vents when you select the  vent mode?
If no then the damper doors for heat or defrost may not working properly and stealing vent air.
If yes then it may be damper doors not properly positioning for the vent mode.
If you can watch the damper door linkage work and all looks good then you might try a
fishing tool up the vent ducts to be sure nothing built a nest in there.
I pulled half a shoe box full out of one. That was when I figured out where that chewed up roll of toilet paper went, they must have been busy!
John Duld
1995 U320C SE 40'

Re: no air out the dash vents

Reply #2 –
Nope, there is little or no air coming out those vents no matter what setting I choose. Either the intake is clogged or the blower fan is not talking to the motor shaft...
Jay
1989 U280 SE, 36', 3208T Cat, build 3292

Re: no air out the dash vents

Reply #3 –
Jay,
I guess I would check for good voltage and ground at the motor.
If they are good it may be time to pull the motor.
John Duld
1995 U320C SE 40'

Re: no air out the dash vents

Reply #4 –
Quote from: John Duld –
Jay,
I guess I would check for good voltage and ground at the motor.
If they are good it may be time to pull the motor.

Jay,
The ground connection on the blower motor is the first place to check as John said. Mine was acting up and then stopped working completely.  I thought it was the dash solenoid which I changed last week and that didn't fix it.

I removed the panel under the dash on the passenger side per instructions by Gary B to get to the motor.  It was only four screws and the panel tilted down for easy access.  The motor was right behind it and the breaker panel was not there to have to remove.  To access from the dash I only had to take one hose loose.  Hopefully yours 
is similar and easy to get to. 

When I was removing the connections to check the voltage, the ground which was connected by one of the screws on the back of the motor was loose from corrosion and could be pulled out with your fingers.  When I tested the blower with the ignition on I noticed a spark and the blower came on when jiggling the ground wire.  I tested the wires for 12v with the meter and that was good so I knew the problem was a bad ground. 

I moved the ground connection to the next closest screw which I tightened up for a good connection, tested several times at all speeds and it is working properly.  I put a bigger screw in the old one and tightened it up.  I was just fortunate that this time a loose/bad ground connection was the problem and I didn't have to replace the motor.  Maybe this is your problem also.  Good luck.

Jerry aka Murph
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Jerry and Cindy Maddux
1993 U300/36WTBI DD6v92TA
build 4271  "Miss Lou"
1995 suzuki sidekick 4x4 toad
Gulfport, Ms

"Pride of Ownership"
 

Re: no air out the dash vents

Reply #5 –
The blower motor is working fine and the squirrel fan is spinning away merrily. The flaller door is letting air in. All I can fighre now is that the distribution box isn't doing its job I mean, when I pull a hose off and can look in there a d see the fan, it stands to reason that air oughtta be rushinv out hes? But maybe all the baffles are open all the time so every vent just gets a trickle so that is what's getting checked next. Meanwhile my new radiator fan showed up so that is the next project...
Jay
1989 U280 SE, 36', 3208T Cat, build 3292