Automotive Air Conditioning Information Forum (Archives)

Provided by www.ACkits.com

We've updated our forums!
Click here to visit the new forum

Archive Home

Search Auto AC Forum Archives

Bypassed Compressor Cycle Switch

tomibriggs on Fri May 02, 2008 7:29 PM User is offline

Year: 1996
Make: Toyota
Model: Corolla
Engine Size: 1.8
Refrigerant Type: 134
Ambient Temp: 74
Country of Origin: United States

Let me start by saying that this is an awesome forum.

The previous owner of my car decided to run a single wire from the compressor to a toggle switch on the dashboard with the other end attached to the ECU fuse. Pressures are perfect & system has sufficient refrigerant. Although the A/C works fine most of the time even better when the car is moving, there are a few things that bother me & would like to try correcting:

1. I noticed that the condenser/auxiliary fan doesn't come on at all. This is porbably the reason why the a/c is not as cool when the car is not in motion.
2. The compressor does not cycle automatically. It is mainly controlled by the toggle switch on the dashboard.
3. The engine does not idle up or compensate for the load when the compressor is on. The idling simply lowers.

I tried reconnecting the original wire on the compressor but the couldn't cycle on the compressor. Where do I go from here? Which component should I test next? Or should I just leave the whole system alone as it is...or atleast connect the condenser/auxiliary fan to a different toggle switch so I can turn it on when I'm stuck in traffic?

Thanks in advance!

Chick on Fri May 02, 2008 8:39 PM User is offlineView users profile

Check to see if it has a light on the ac controls, and if it comes on when pressed. A lot of those cars will have a snowflake when the AC is called far. Could just be a bad controller, haven't seen one done likethat it a long time, especially on a newer japanese car..Check fuses too..

-------------------------
Chick
Email: Chick

---------------------------------------------

Freedoms just another word for nothing left to lose

tomibriggs on Sat May 03, 2008 5:25 AM User is offline

Thanks for the response.

There is light on the a/c control switch when pressed. Does this mean the switch is ok or should I try jumping it?

I have check the fuses & relays they're all ok. What next? My car is equipped with a thermistor - should I try bypassing that?

Chick on Sat May 03, 2008 5:42 AM User is offlineView users profile

You are going to need a wiring diagram for that car and trace the wires from the control head all the way to the compressor. I would not fool with the thermistor, as the car is computer controlled, and you could cause problems. I would suggest a subscription to Alldata repair manual for your car. It will also have the testing procedures to find were the break is. The light on the dash is a good sign that the controller is working, but the signal may not be leaving it, thats why a good diagram and test procedures are a must. Since the compressor is being controled by the toggle switch, the computer isn't getting the iformation needed to turn the fan on, it should be fixed properly..Hope this helps.

-------------------------
Chick
Email: Chick

---------------------------------------------

Freedoms just another word for nothing left to lose

tomibriggs on Sat May 03, 2008 1:34 PM User is offline

CORRECTION to my previous post. The a/c switch has NO light both ON anf OFF position. It has a wiring harness on the back with 5 color coded wires - white, blue, yellow and 2 greens. Which wires do I jump to hotwire the switch to test it and find out if its still good or bad?

I have a Haynes Manual that has a wiring diagram. Unfortunately, it does not discuss testing procedures to find where the break is. What if I simply replace the thermistor with a new one instead of attempting to jump it? Besides the relays, would you say that the thermistor is the most likely the culprit?

Edited: Sun May 04, 2008 at 4:13 PM by tomibriggs

Back to Automotive Air Conditioning Forum

We've updated our forums!
Click here to visit the new forum

Archive Home

Copyright © 2016 Arizona Mobile Air Inc.