Vacuum head lights

[4Bangin69]

Recently I replaced my intake manifold with a high performance one. The head light doors worked perfect before with the original intake, now the doors will open with no problem but will not close. It will not reverse the vacuum to close when the switch is turned off. Did the switch go bad? And why.

[A383Wing]

or you broke the "close" vacuum hose to the front of the car

[myk]

Check the easiest things first and go over your vacuum hoses.  Depending on the condition of your hoses and tee's any one of them could have easily been knocked off...

[elacruze]

Mine still has the original hoses, and every so often I get a split on the 'close' hose near the driver side headlight. It's hard to see but stops the doors from working. Get a good light and magnifying glass if you need it and look at every hose end where it connects and divides.

[4Bangin69]

The doors still have vacuum to them when I turn them off.
  So when I turn on the car the doors open.  Then with the car on I turn the switch off. The lights turn off but I still have vacuum to the doors .For me to close them with the car on I reverse the lines under the hood.
 
There is constant vacuum to the lines. So right now they are reversed to keep then closed.

[69wannabe]

Sounds like the vacumm part that is on the headlight switch has broke the little part that changes the vacumm from close to open when you turn the lights on and off. You may can lay in the floorboard and get someone to turn the lights on and off and you may be able to see if the vacumm part is swicthing back and forth or not. Or you may have to pull the instrument panel to get a better look at it.

[8WHEELER]

Check to see if this arm on the side of the switch is still there and working, as said above.

Dan