A/C Troubleshooting

[RedBeardedDevil]

I have been looking over the forums and I was wondering if someone can post a simple point to point way of diagnosing A/C-Heater problems? I get neither heat nor A/C through the defroster and nothing through the dash. I am pretty sure the resistor by the passenger foot is shot. I am also pretty sure I have a vacuum leak somewhere. I need an Idiot's Guide lol. I don't have much time left to find and fix the problem(s).

 

[BrApple]

if the resistor is shot then teh fan will not work.

if you get defroster only then its typically a vacuum supply problem to the hvac.

 

[Tony2005]

If no air/or heat is coming out of any vents, then you may have a broken fuse, switch or blower motor. Remove the blower motor and hot wire it to the battery. If it works, the problem is the switch or wiring.

http://www.autozone.com/autozone/repairinfo/repairguide/repairGuideContent.jsp?chapterTitle=Heating+%26amp%3B+Air+Conditioning&partName=Chassis+Electrical&pageId=0900c152800a8c41&subChapterTitle=Blower+Motor&partId=0900c152800a8c0e

 

[RedBeardedDevil]

Which lines should I be checking, and is there a good method for finding the needle in the haystack?

Edit: THanks for the Autozone link. Very helpful.

 

[projectSHO89]

if the resistor is shot then teh fan will not work.

....

If the resistor is open, you will get high speed only.

If the switch connector is melted, you'll get nothing.

Steve

 

[RedBeardedDevil]

To clarify: I get air through the defroster vents only. I can get low - medium - high air through them. The heater will not heat, and the A/C will not cool. So that means that the blower motor is fine, correct? So I need to concentrate on vacuum lines and maybe the a/c blend door actuator right? I am going to take the dash and everything apart again tomorrow. I just got done with a coolant flush and fill. Is there only one line coming in to the cabin for vacuum? The one running in with the heater hoses? I managed to get under the car (no small feat considering my size lol) and saw that it was intact. I have read and printed out the Autozone guides regarding a/c components but any further info is appreciated.