Heater/defroster not blowing hot air....HELP

On my way to work this morning there was a lot of moisture on the windshield, I usually turn the temp to hot and turn on the defroster until the fog/moisture starts to clear up, but this morning there was no heat? The thermostat is new and my water temp was normal. Radiator was flushed and refilled not that long ago. There has been some noise coming from behind the dash like an actuator cycling. Wondering if my A/C-Heat control unit is going bad? Anyone have this problem or can help with a solution.

Thanks,
Ron

 

I'd check the cable that runs from the unit (located on the side near the gas pedal) to the regulator/butterfly valve/whatever-you-want-to-call-it on the opposite side of the firewall. Adjust the thermostat while the truck is running and watch to see if the cable and/or valve does its thing.

I hope that helps because I pulled that out of my @$$, so take it FWIW haha

Only other thing I can think of is a new heater core.

 

I have the same noise here lately, people have said its the blend air actuator. When it starts to go bad it will start cycling back and forth. I need to try my heat and see if i have any. Havn't done that yet.

 

Thanks guys, I plan on checking everything when time permits. I'll keep this posted with steps and progress.

 

Please do since we both have the same issue, some insight as to how difficult it is to change, ect. I may look at mine one evening this week.

 

Well after a little search, i found this post which seems to show a detailed photo of the blend door actuator, does't seem like its hard to reach at all from the pics. Anyhow, visual place to start. Mine only seems to start cycling in the mornings, not any other time.http://www.tacomaworld.com/forum/1st-gen-tacomas/114920-what-part.html

 

I've been hearing a weird noise like that too lately, sub'd for the outcome. I haven't noticed anything else weird but I haven't had it while it was cold enough out to have the heat on either.

 

Well when i got home today i turned on all settings and everything is working fine, defrost hets hot and heater blows hot, recirculate is working and A/C gets cold. Mine has only started cycling a couple of mornings but doesnt seem to do it in the afternoon. IDk, guess i'll go on and deal with it if it completely takes a shit on me in the middle of winter on a cold morning. Just my luck!

 

Tomorrow I will have a chance to crawl under my dash and see if I can locate the problem. I'll post the results of my troubleshooting.

 

I had the same noise behind my dash a couple years ago. When i pulled my actuator out it would just turn back and forth as if it didnt know which temp i had turned the dial to. Since then i just have taken the actuator out and have been manually changing the blend door.

 

I was leaning in on the passenger side with keys in the ignition and power on and started cycling the temp. I could hear the actuator getter power but nothing was moving. I tapped the actuator with a screwdriver and it opened. I started the truck and went for a drive and it seems to be working now. I'm gonna buy an actuator and have it on have in case it goes completely out. Hope this helps to those that have the same issue.