Heater and A/C Inop after changing out heater core

[JMac's]

Need some help!!

I just got done replacing my heater core in my 1990 K5. Now the heater or A/C will not work. Can someone give me some advise as where to start?

Thank you,
JJ

 

[British Slave]

What do you mean by doesn't work? Just guessing, I would say you blew a fuse, left a vacuum line off, got vacuum lines on the wrong vac motor. Broke the door link.

 

[JMac's]

i did check the fuses. Everything was good under the drivers side dash panel. I just got done checking the vacuum lines to make sure that they were connected. As for the blend doors, is there a way they should be when the heater or A/C is on??

 

[British Slave]

 

[British Slave]

 

[British Slave]

It's very easy to get vacuum lines H and I reversed.

 

[JMac's]

I just checked that switch. I have power to it. When I turn the switch from off to ac/vent/of floor, you can here a very soft noise and then it goes away. As for when I turn it from low to high. Nothing happens there also.

 

[British Slave]

Are you saying the fan doesn't blow?

 

[JMac's]

I will try and switch H and I first.

 

[JMac's]

Correct. The fan is not even blowing.

 

[British Slave]

That is a different problem.I has to be:
fuse
wire unplugged
bad connection
bad fan motor
wire broken

The vacuum lines have nothing to do with the fan blowing.

 

[JMac's]

I am thinking the same thing. I just tied to turn on the radio and it came on but no sound is coming out. I did reach back there and I heard sound for 1 second. It must be a loose ground some where......

 

[JMac's]

Thank you everyone for your help in this matter. I was able to get the A/C and heater working today.

 

[British Slave]

What was the problem?

 

[JMac's]

The vacuum lines were on installed correctly. After tracking down the blower not working. The purple wire that goes from the relay to the blower motor was pulled loose.