Since i have had my truck the blower doesnt come on at all when i try to turn the switch on. I located the blower motor unplugged the connector to it (2 wire). First i jumped straight to the blower motor wires and i got nothing. Also checkec that other connector with key on blower on no power there either ? Where do i go from here.

Also appears that white rubber vacuum line that goes through the firewall and then to some kind of plunger deal in the very corner of the engine bay to the left and above the blower motor is all weather rotted.
And a black vacuum line thats not hooked up.

 

Do you have a speed control resistor located in the plenum?
Is it intact?
If you tried 12V direct to the motor I would guess that motor is toast.

The "plunger deal" is the fresh air mix door and it's actuator.

 

im not sure about the speed control resistor the plenum should be in stock form though. Where is this control located on the plenum?

 

The resistor pack is located just to the right of the blower motor. Pull the screws, and the whole thing lifts out. The resistors may be bad, but since they are there to give you the slower speeds on the fan, you should still have high speed.
First thing I would check is the fuse for the heater /ac. Then I would check the motor. If I understood your post, you applied 12 volts from the battery to the blower and got nothing? If this is correct the motor is bad, but you have another problem somewhere, or you would have shown voltage after the resistors. Perhaps the motor failed and blew the fuse, or the switch/wiring is bad.
The white vacuum line needs to be repaired. If allowed to leak, this will cause all the air from the blower to go to the windshield defrost no matter where you move the lever. The black line that is not connected needs to be chased down to see where it is supposed to go. If it has vacuum on it and is sucking from the atmosphere, at the least you need to plug it until you can determine where it is supposed to be connected.
A u-pull yard is a good place to pick up a blower, resistor pack, and see where the vacuum lines actually connect.
It is always a good idea to post the year truck you are working on too.
Good Luck Frank

 

i will probably pick up a new blower motor and test the switch. The white line is so messed up i will probably have to run a whole new one through the firewall if possible.
The black vacuum comes from the same bundle the white one does. And its not hooked up to vacuum right now. It is suppose to be but i dont know where it goes. I can never find a good in depth vacuum diagram other than the one under hood.

 

Someone might have a vacuum diagram if they knew what year you were working on eh?
Frank

 

90 ford f150 302. All i have ever seen was the underhood one.

 

Send me a pm with your email addy if you have high speed internet
I have the 1990 electrical and vacuum manual as a very large file.
I'll have to find the file to see exactly howbig it is.
The black line in question is probably the supply line for the heater controls. The end under the hood looks like it connects to the vacuum distribution block.
Frank

 

I guess what I meant to say is 'have you checked for power *coming in* at the plug for the resistor pack'

On my truck manifold vacuum comes from a port at the back of the intake manifold to a distribution block at the top center of the firewall and from there enters the cab beneath the heater hoses. Comes back out from the same place and goes to the vacuum actuator by the passenger side hood hinge.
I have heard that some trucks have a vacuum accumulator (think storage tank) that looks like a coffee can mounted on the fender.