Dual Zone Climate Control Issues

I am having an issue with my AC/Heater not working intermittently. Some times it comes on as usual and sometimes not at all. I checked the refrigerant and it is well within the specifications. Has anyone had this issue? My old Tacoma had an issue with the resistor that was bad but it would only blow on high. This time it doesn't come on at all at times

 

What's the details on your truck? Year, mileage, etc..

Is it the blower that's intermittent or is it the temp? You mention the blower resistor on your old truck so just want to clarify. And is it all the settings that are messing up?

 

More information is needed. There are several factors that can cause this that are still considered to be normal operation.

For example, there's a setting in the head unit to turn the AC on by default with other temp settings.

Below certain temps your AC won't run anyway so your climate controls will forgo trying to activate the AC.

Also, when it is cold and your HVAC system is set to "auto" your HVAC will wait until some heat is built up in your engine before actually beginning to blow air.

 

The settings are staying the same. The blower isn't coming on and I am not seeing or hearing the compressor kicking on

 

First place to look might be the fuses

 

It's not the ambient temp. I have had this truck for 6 years now. it just started doing this about two weeks ago. Sometimes it comes on and sometimes its off. The display says its on but there is nothing happening if that makes any sense

 

Do you guys think it could be a relay?

 

ok this might be a little odd, but look at the AC compressor. On the right side of it you will see a grounding stud and a bare wire coming off it and going behind the clutch. Look at the bare wire part it and see if its green with corrosion. This can cause the system to fail if it doesnt have a good ground.




Here is a close up of what a bad ground would look like on that connection. The wire under the shielding has actually lost all connection.

 

hmm Let me check that

 

Below certain temperatures your AC won't work regardless of the indicator light. It's a safety feature to protect the compressor when the pressure gets too low. Not sure if it is related or not.

Not sure about your area but most places around here do free AC diagnostics. It could rule out a few things.

 

Their location is listed as Corona CA, thats southern California nearly Mexico. I dont think cold temps is a issue there.

 

Thanks for that. I know it can reach down into the 40's and 50's sometimes so I wasn't sure.

 

LOL heck this morning around 9:45 I noticed it was a freezing 67 outside decided to try the
heat and scratched my head. No 'heat-button' to push like an 'ac' button. So I just dialed up
the 'temps' and sure enough started to feel a little hot air coming out.

I'll probably use the 'heater' 30 days out of a year here.

 

I dont think there is a single car made that has a "heat button"

 

Guess I'm showing my age... perhaps I'm confusing it with a slider bar or something from back in the 70's...

 

That might be it, pretty much all cars either had a slider with hot on one side and cold on the other, or a dial with hot and cold or buttons to turn up/down the temp.

My 1973 dodge challenger has a slider for hot/cold (no AC) but my 1991 BMW has a dial with hot on one side and cold on the other. My wifes 2005 lexus has a button with a arrow up and arrow down, those control the temp.

 

This thread is bringing back memories of my 77 Trans Am. The Climate Control slider was labeled Vent, Heater and Defrost. I believe Heater meant the warm air was forced out by your feet.

https://images.app.goo.gl/AEzSet7WLu4gd7Cc9

 

So after all of the problems it was the blower motor. It was intermittently shutting off and turning on. I replaced the motor ($118) and now it works great.