truck is an 05 lly, the blower heater sounds strong on 5 , but is very weak on 1- 4 settings no air flow on setting 1 . even on 5 it is not how it use to be. i pulled the resistior, and it looks ok i do not see anything that would suggest it is burned out.
suggestions??

craig

Unless the resistor caught fire and burned up, you can not tell if it's good by looking at it. Replace it.

If it is not working on the lower settings, I would say resistor also. If it works on all settings, but doesnt move much air, you could have a door that is not sealing properly, and/or the evaporator and heater core, could have a bunch of dirt, and other things blocking the air flow.

well i replaced the resistor, and its still the same. little air movement on 1-4, and 5 sounds great but int not how it used to be. does anyone know how to check the doors in the dash?? on should i check somthing else?

When you have the selector switch on one setting only such as vent, floor or defrost, feel the other vents to see if there is any airflow from them. If there is, your mode selector door is not switching properly. If there is only airflow from the vents you have commanded, then you may have an airflow restriction such as a dirty evaporator/and or heater core. Whats the history on your truck as far as the type of enviroment it has been operated in.

Riley

clean freeway driving 99% of the time. it had the dash out twice to replace the foam seals in the duct work because of whistling, but its been fine for about a year. the truck is kept clean inside and out.
its out of warrenty now so any i will have to do any dash disasembly.:(

any more suggestions??

thanks
craig:help:

Have you checked the airflow from the vents yet? What does your blower motor sound like when its running? Does it sound normal, does the dash vibrate when it is running?

resistor

Defrost is the default setting for the duct work. Set it defrost and see if the airflow changes up as you turn the fan switch from 1-5. If that's a no-go, then I would suspect the blower resistor connector has lost tension in several of it's terminals. Unplug the connector and, witha good light, inspect inside of each square terminal. The contact portion is a ramped/sloped portion within each square. It must touch the oppsite side of the square as you look further in. Also, any signs of distortion of the connector body are also a tattletale sign of loose terminal. GM sells a replacement plug (I'm sure, as the plug melted on all of mine). Be prepared for sticker shock (the plug, IIRC, is more expensive than the resistor). Harness repair plug ........P/N 15862656 or ACDelco P/N PT2195. Call around for the best price, assuming yours is bad. There is also the possibility that your new resistor is bad. I'm still betting the old resistor took the plug.

i will check the plug , and also the air flow on defrost. the blower sounds great on setting 5, below 3 you can hardly hear it. no odd noise, or vibrations. the way it sounds on 4 or 5 it seems like the problem is in the duct work.

If the plug is good, perhaps the Heater/AC needs reset. Disconnect both battery negatives and set them so they don't touch the battery posts. Now take one negative and touch it to it's respective positive for 2 seconds. Connect all the batt cables back up, reset your clock, and try the vents. If it's an actuator problem, it will have gone away, albeit temporarily.