1996 Tacoma Air Conditioning Advice

So, I've had some issues with my AC for the past two summers, mostly that it didn't work. Me and my father replaced the evaporator thinking that was the issue, and it wasn't. We got frustrated not knowing alot about AC systems and thought it just needed to get a Evac and refill. I bring it into Big O Tires, and they charge us 65 bucks and tell us the AC works fine, its just the heater control valve is broke, so its letting the radiator fluid through.. I was suspicious, but I replaced the valve even though it looked perfectly fine, and it was perfectly fine. Next, I brought it to a different place (Gary's Oil City), and they called me and told me they filled it all the way up and it never got cold, so they figured out the compressor was broken because there was either no high or low pressure (cant remember which one). The compressor clutch works perfectly fine, although is there something inside that could be malfunctioning? Another thing to mention that may or may not be important: When I replaced the Evaporator, it didn't have a spot for the same switch that plugged into the old one (High Pressure Switch?), so I just put a cable that connected both and electrical taped it, but it still triggers the compressor to come on, so I don't think thats the issue.

 

Did you replace the expansion valve when you replaced the evaporator? And i am almost positive, you have to have that pressure switch connected or the system will not make cold air. That's why they told you there is no low or high pressure and with that, no cold air either.

 

Yes the expansion valve was replaced, and I don't believe it does have to be connected. I connected the wires together, so it is always sending the signal back, the compressor only started working after I did that. My current evaporator doesn't have a spot to plug it in so I had to do that.

 

Did the old evaporator have the switch on it?

 

Yes, but the AC also didn't work with the old Evap, which why I have ruled it out as a issue.

 

Here , this is small part of article on a/c pressure switch
2. Unable to cool the car
If either of the AC pressure switches fails, then the system will have a difficult time maintaining the pressure required to function properly. If the pressure is not right, then the AC system will not be able to produce the cold air required to adequately cool the cabin. You may notice that the cabin takes longer than usual to reach the correct temperature, or may not even be able to reach the correct temperature at all.

 

Thing is, you actually never knew why it wasn't throwing cold air, even with the old evaporator. You and your father replaced it thinking that was the issue. Gary's tell you there was no pressure in one of the lines, points back to the pressure switch. The one on your old evap could be bad. Im not a a/c expert either but, i be certain to say, you need that pressure switch on there. Yours might different as you can see in picture, my switch is mounted on high side line. I would think yours is too even being a 96

 

Hmm. Yes I believe that is where it should be mounted, although the current one I have didn’t have a spot for one. I’ll look into it tomorrow, thanks for the info guys.

 

It just seems like since I hotwired the pressure switch, it shouldn’t be an issue. If the switch has a cable running to itself, it should be telling the compressor to just turn on. I don’t believe the switch has variable voltage, it either tells the compressor to turn on, or not turn on. I only got the compressor to work when the wire was jumped between the two prongs on the switch.

 

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Warning:




anyone know where to buy those two hardlines?

 

toyota

 

Warning:




anyone know where to buy those two hardlines?[/QUOTE]

Salvage-yard or dealer. Last year, When I was installing AC in my '96 Tacoma, I got a used evaporator where someone had wrung off one of those lines. The dealer wanted more for just one line, than what it cost me to buy another complete used evaporator unit, complete with housing, circuit-board, and undamaged lines.

As for the OP's problem, the correct Tacoma evaporator has very short connector lines, to which is fastened the expansion valve. The two lines, including the one with the pressure-switch, are separate parts and attach to the expansion valve. (See the photo posted above)
Unless they're damaged, normally those lines, along with the switch, are re-used when replacing the evaporator.

Also, with any major work on an old AC system, the filter-drier, located to the left of the condenser, should have been replaced. Was this done?

Otherwise, if the compressor is engaging and the system is operating, high & low side pressure readings would help indicate where the problem is. You can get an inexpensive AC gauge set at Harbor-Freight, or pay a shop again to test this. After 22 years, the compressor could be worn out.

Happy Motoring, Mark

 

Do I need to take those readings with Freon in the system? They took all the Freon out when they said it didn't have pressure, and still charged us for a Evac and Recharge.... I believe I can use the top off of one of the old AC bottles in my garage for that correct, I thought I saw somebody doing that.

 

If they evacuated the system the only thing you can do is pull a vacuum and check your gauge to see where its holding, where it holds vacuum depends on your elevation.

edit: sometimes it could be -28 and sometimes you get a full vacuum of -30.

 

Warning:




anyone know where to buy those two hardlines?[/QUOTE]
Seen some on ebay Wolf. But all are connected to evaporator.

 

So it seems like everything i've read says that if the compressor clutch wheel is spinning, it is working correctly, could the compressor be malfunctioning inside even if the clutch wheel is spinning?

 

Good question, I havn't seen anything to say otherwise.

 

Thats what I was thinking, although the guy the worked on my truck said it wasn't giving out any pressure, and I needed a new compressor. I don't want to drop $120 if that isn't the issue because I have already got screwed out of $350 because nobody can figure it out.

 

Ok, did you get a pressure switch connected?

 

No, but like I said I don’t think that is the issue, and until I’m certain it is I’m not going to do it because it requires me to put in a new evaporator. The pressure switch is either on or off, that’s why in my opinion hotwiring it shows that it isn’t the issue. I just started the truck turned on the ac, and then checked under the hood and the compressor clutch wasn’t spinning, then I put a little red wire and jumped it, and the compressor clutch was spinning.