Blower fan speed problem

[Smitty1021]

kind of a weird problem today. Had my AC going with 0 issues yesterday. Hop in the truck this morning and the blower isn't working at all. Found out the ground wire is faulty somewhere in the circuit. So I jumped the ground but now the blower won't work on Hi. Any ideas?

Also noticed that before today, recirculation was always lit up and now it won't even come on if I hit it. Starting to wonder if the controls are screwed up.

 

[GaryCCR]

Sounds like the blower motor resistor.

 

[dmhscorpion]

kind of a weird problem today. Had my AC going with 0 issues yesterday. Hop in the truck this morning and the blower isn't working at all. Found out the ground wire is faulty somewhere in the circuit. So I jumped the ground but now the blower won't work on Hi. Any ideas?

Also noticed that before today, recirculation was always lit up and now it won't even come on if I hit it. Starting to wonder if the controls are screwed up.

The high speed setting runs through a relay. See this schematic.
https://ww2-secure.justanswer.com/uploads/tracker40/2012-02-06_221504_1.gif

 

[moremudd]

Hi, I am having the same troubles , but with my truck the actual blower speed selector switch melts and wont let me have high speed until I put in a new selector switch , I found the wires were discolored and very stiff at the terminals so I replaced the pig tail but the darn switch keeps melting , I have replaced the resistor, and the blower . The blower is not drawing excessive voltage . Maybe your switch is doing what mine is . There must be a way to protect the switch from the high amp draw so it stops melting , I thought that was what the relay was for but I'm not completely sure how to diagnose the melting switch problems , hopefully one of the gurus on this site will advise us on a fix .

 

[Smitty1021]

So far each response is the only 3 things I have left to look for haha. I was thinking relay or resistor but as I'm thinking about it, my controls on my panel are acting up. The recirculation button won't work. The truck won't provide hot air making me wonder if the module is triggering the blend door at all. It almost feels like my AC is constantly on. Have a couple spare hvac control panels I'm going to try first before replacing the resistor and relay.

Prior to looking at the schematic provided above, does the ground wire only ground for the blower motor or does it act as a common ground for the entire hvac control panel?

 

[Donnie Smith]

I too am having some strange issues with my A/C blower system. Got in today and drove into town and back with no issues. AC blew fine at different speeds. Came back out 30 minutes later and had now blower motor speed control. Hooked up 12v and ground to blower and is turned on no problem. Blows full blast. So I replaced the blower control switch and the blower relay. All seemed to be good so I started into town again. About a mile down the road and the blower control switch stopped functioning again. So I continued into town and purchased another relay and switch and this time a resistor. Replaced all those parts and now it's back to blowing. Not sure how long. Will see in the morning when we head out. Hoping problem fixed. We'll see. Any one had such issues?