AC doesn't blow cold air?

Tiny
JBRASIEL
  • MEMBER
  • 2005 TOYOTA TACOMA
  • 112,000 MILES
I just finished installing a new stereo in my 2005 Toyota Tacoma - I had the AC Control unit out because that is how you access the stereo to install a new one.

When I replaced the AC control unit the AC button light and the outside air circulation button light would not light up. I removed the panel and checked to see if the connections were plugged in correctly. All was good there so I unplugged them and I made sure they were lined up correctly and carefully plugged them back in again and still no lights on either switch.

I turned on the vehicle and turned on the AC. No AC defroster only.

I checked a few of the fuses under the secret door on the driverside lower dash. None that I checked were blown. I wasn't sure what each of the fuses were for.

Is there a main fuse blown or is there a fuse inside the unit that needs replacing?

The abbreviations were not something I recognized. Do you know which fuse it could be or am I going to have to look at all of them to see which one is burned out?

Is there a solution for this?

Thanks for your answer,

Best,
Jim
Do you
have the same problem?
Yes
No
Saturday, August 17th, 2013 AT 12:30 AM

7 Replies

Tiny
SATURNTECH9
  • MECHANIC
  • 30,870 POSTS
Hello,

It sounds like you have a heater relay that is out but to be sure lets check out this guide. Check the fuse labeled ig1 in the fuse box on the left side of the dash.

https://www.2carpros.com/articles/how-to-check-an-electrical-relay-and-wiring-control-circuit

This video can help as well

https://youtu.be/4UjfQKvrB6Y

Here is the air conditioner wiring diagrams and the heater relay location so you can run some simple tests.

Check out the diagrams (Below). Please let us know what you find.
Was this
answer
helpful?
Yes
No
+2
Saturday, August 17th, 2013 AT 8:08 AM
Tiny
JBRASIEL
  • MEMBER
  • 2 POSTS
Yep you nailed it! I replaced the heater relay now everything works what great site this is :)
Was this
answer
helpful?
Yes
No
+1
Saturday, August 17th, 2013 AT 9:54 PM
Tiny
SATURNTECH9
  • MECHANIC
  • 30,870 POSTS
Good to hear, please use 2CarPros anytime we are here to help.

Cheers
Was this
answer
helpful?
Yes
No
+6
Sunday, August 18th, 2013 AT 7:28 AM
Tiny
ALLENCT
  • MEMBER
  • 1 POST
  • 2001 TOYOTA TACOMA
  • 4 CYL
  • 2WD
  • MANUAL
  • 12,800 MILES
My AC unit loses cooling ability over a long drive. It works just fine for short trips of 15-20 minutes. If it is running for 20-30 minutes it loses its ability to cool. The fan works but blows warm air. When this happpens, if the truck sits for a while, the ac will work again. What might the problem be?
Was this
answer
helpful?
Yes
No
Monday, October 12th, 2020 AT 6:44 PM (Merged)
Tiny
RASMATAZ
  • MECHANIC
  • 75,992 POSTS
Faulty low pressure cutout switch. This switch prevents the compressor from running if the refrigerant level is low. If the cutout switch is not reading correctly, it can prevent the compressor from coming on.

Faulty compressor clutch. The magnetic clutch on the compressor requires full battery voltage to engage. If the voltage to the clutch is low, or the clutch coils have too much resistance, or the air gap in the clutch is too great, the clutch may not engage to drive the compressor.

Faulty compressor clutch relay. Check to see if the relay is receiving voltage when the A/C is turned on. Also check the relay wiring and ground connections. If bypassing the relay with a jumper wire or routing battery voltage directly to the compressor clutch makes the A/C work, the relay is probably bad.

Faulty A/C control switch. The switch may be worn and not making good contact when it is turned on.

Some possible causes of intermittent cooling (or no cooling) on automatic A/C systems include all of the above, plus:

A problem in the control module or control head (this usually requires using a dealer scan tool to read fault codes and perform self-diagnostics).

A bad temperature sensor (an ambient air temperature sensor, interior air temperature sensor, evaporator temperature sensor, or sunload sensor). Again, a factory scan tool is usually required to perform diagnostics on the system.
Was this
answer
helpful?
Yes
No
+2
Monday, October 12th, 2020 AT 6:44 PM (Merged)
Tiny
BOCKERMAN
  • MEMBER
  • 1 POST
  • 2000 TOYOTA TACOMA
  • 3.4L
  • 6 CYL
  • 2WD
  • 227,000 MILES
2000 Toyota Tacoma 6 cylinder Two Wheel Drive Automatic 227,000 miles

My air conditioner will work when it wants to. I will be driving along with air blowing nice and cold and then gradually, I notice the cold air start going away. It still blows but the air gets warmer until its blowing ambient air temperature. It is not hot air from the heater, but just plain, un-cooled air. I check the compressor and it is working. It goes on and off like normal when I turn the air on or off. After the car sits overnight, the air conditioner will work again just fine. The symptoms also seem related to how hot it is outside. The issue occurs more frequently when its really hot out. It just seems that something is intermittently choking off the flow of Freon to the evaporator. Then all by itself it opens back up (by resting the truck overnight) and the a/c works perfectly again. The hotter it is outside, the more often the symptoms seem to occur. From what I can figure out. My guess would be the expansion valve. And then work fine for several days before it shuts off again?
Was this
answer
helpful?
Yes
No
Monday, October 12th, 2020 AT 6:44 PM (Merged)
Tiny
WRENCHTECH
  • MECHANIC
  • 20,758 POSTS
It sounds like the compressor is going out but this video will help us tell for sure.

https://youtu.be/4UjfQKvrB6Y

Please run down this guide and report back.
Was this
answer
helpful?
Yes
No
Monday, October 12th, 2020 AT 6:44 PM (Merged)

Please login or register to post a reply.

Sponsored links