I recently replaced the spark plugs and pcv valve on my 1997 Ford Expedition, and during that i had to take off other things to get to all of them. Well now when the truck is under acceleration the ac diverts from the panel vents to the windsheild defrost. Can anyone tell me if i have a vacum line in the wrong spot, connector not all the way connected or is there just more to it?

 

It may be a vaccum leak.Or if you swichted one or two use the diagram sticker under the hood to correct it.

 

sticker under the hood? hmm... would the fan clutch switch have anything to do with the problem?

 

I dont think it has anything to do with it. It sounds like a vacuum problem.