Hey..
I've done some reading up on here, and learned a few things after trying to figure out what is wrong with my heater and a/c blower system. Anyway.. Last weekend, I was out and about, had the A/C going. I went into the store, came back out, started the truck.. and nothing. No Air flow at all from the fan, both heat and a/c, nothing. So, I just drove home so i could look at it, I disconnected the battery, checked all the fuses, they looked fine. Pulled the Blower Motor Relay, and plugged it back in. Hoped on here, and read around alittle bit, figured it was either, Fuses, Relay, Resistor or the motor itself. Wanted to start with the cheapest, headed to town to get the Relay, suddenly before i got home i tried it again, and it all worked perfectly! The next morning, it worked fine, in the afternoon on the way home, started up the truck and it didn't work. Got home, disconnected the battery and put the new relay in there, and started the truck ,it all worked fine.. At that point i figured i had fixed the problem.. But today after work, same thing. SO, I am wondering. I know the resistor controls the speeds of the fan, could this be my problem?( i didn't think so because WHEN it does work, it blows properly at the selected speed) I didn't want to go ahead and replace the Blower Motor itself just yet because it works sometimes, and sometimes it doesn't and it seems strong when it does( it could still be bad, i'm not sure) What does this sound like to you more experienced guys? The Heater/ fan/ a/c only works sometimes? I would appreciate ANY input. My next step was to change the resistor or the motor, what do you guys think it is?
Thanks alot if anybody could help

 

Basically, I've got it narrowed down to a few things that i think it could be, but i would like to get some input from some of you who have already had experience with these sort of problems.

Fuses are good,
The new relay didn't seem to have fixed the problem
I suspect the motor is good since it does blow when it actually works
I don't know much about the resistors?
It's only been doing this the past week, it will work, then other times not.

 

Below and to the right of the blower motor is where the resistor is mounted.
Remove the plug and clean the terminals as best you can, they get corroded and rust away to nothing over time.

 

My HVAC issues were from the resistor pigtail. Mine was MELTED to the resistor. Autozone has the pigtail and resistor for $12 each. get them both and some butt connectors, wire stripper, and a crimper and get to work. Have fun.

 

You are going about it the correct way. Keep in mind, it could very well be the blower. The blower motors can develop a "dead spot" on the armature. When you take it a part, you rotate the motor a bit to move it away from the dead spot. The next time you turn the A/C on, it works fine and keeps working because momentum keeps the motor spinning past the dead spot. When you turn it off and it stops on the dead spot again, it won't start.

Sometimes you can spray a little electrical cleaner into the vent hole of the blower and squeeze some more life out of the motor, but seems ready for replacement.

 

x2

Tap on the motor when it does stop, see if starts up.

 

Robert, That's a very good point! I didn't think too much into that, but it makes sense. You said when i turn the fan or truck off it stops on the dead spot, and then will not start because it's on the dead spot, and then taking it apart moving it off the dead spot, then it works. That makes sense, but i haven't taken it apart or anything, or even tried tapping it to get it working. It'll just start working again next time i try it, Do you think it still could be the motor? I have the resistor that should be in tomorrow at autozone, i'm going to try that next.

 

It's REALLY hard for me to say what it could be. I've read up some, and learned a bit. I also, wonder if it is actually in the Blower Control Switch, inside the truck. I just started thinking about that.. It could be shorting out or something

 

Try the Resistor Pac Terminals before the blower, once you are sure it is the terminals do the following:
Someone on here made a suggestion to me to do this once I change my Resistor pac over.
Cut the connector off of the Harness that goes to the Resistor Pac.
Mark the wires, cut the connector off, clean the terminals, slide a piece of Heat Shrink on the wire the type with adhesive inside, solder the wires, clean the connections and shrink the Heat Shrink until you see adhesive melt out the end, DONE !