95 Taco help with air conditioning

95 Tacoma 3.4 v6 291k

A few weeks ago I noticed my AC getting less cooler. Now I crank truck up with ac blower maxed and AC light on, compressor will engage about 2 or 3 minutes after on. Then it will shut off and on periodically staying on for a brief few seconds then shut off. The past few days this would continue. The only difference i can see is once I'm cruising 40-45mph and about 15 or 20 minutes into the drive it seems to stay on consistently. Is my compressor about to seize? Do I need to replace it? Any help appreciated... New member who is trying to 're do my old yota. Motor is pretty dang sound and am about to drop some money into it via tune up.

Thanks

 

Sounds like it's low on freon.
A good evac and recharge with dye will set you up for a system test and leak detection in the future.
You didn't mention any strange noises.
Something that is not a do it yourself.
They will be able to check pressures and see if the compressor is weak etc.

 

Thanks Mike,

Not that it's comparable to a pro doing it, but I purchased a "ac-pro" kit and checked the system. Per directions it says charge half the bottle into the system if the compressor wasn't spinning. I have done that and still no obvious fix. Definitely no loud squeals from the compressor, the blow motor makes a slight tick/knock noise... But regardless air blows on all levels. So I doubt that it's apart of the problem but assume it's going soon as well .

 

A co worker of mine who was a mechanic previously for 25+ years is going to look at it on Monday. I was just hoping to get a head start on it. We're doing the timing belt kit,fan clutch, valve seals, belts, and manifold gaskets next month. I'm pretty confident in his ability.

 

Well then this is the best time to check it out and check for a full charge and double check the system.. Once you evaluate it and get a diag then you can do everything at once if it needs a major component.
Ac is something I really don't like to see untrained people play with. I know they have the kits and such but I have seen some strange things and it's scary.
Don't blame you for trying one though. Hope you find the issue without having to dig to deep.

 

Just an update.

I pulled the blower motor out and its working fine, all speeds of the fan work. Occasionally it makes a ticking or knocking noise.

I've figured out that the truck is trying to turn the compressor. You can hear a difference when the computer attempts to engage the clutch. It will turn on then cut off a second later, then stay on for 20 seconds then off and is just intermitted with no pattern. Its trying to work, but something isn't letting it. Until I can test the connections between all the components, I'm assuming its a electrical problem or maybe the bearings in the clutch/pulley are shot? Anyone else can hit on this?

 

Also bypassed relay and it is still attempting to engage.

 

Just from my experience: my compressor clutch just locked up one day without any warning. I drove somewhere with it working and started it up to leave and it was locked up. I doubt any bearings or pulley are the culprit because I think you'd hear it. I think its a freon issue. My ac cuts on very sporadically and it works very well.

 

You have safety features built into the system. Low pressure or high pressure will disable the clutch.
If it's trying to work then a low freon issue or cycling switch could be an issue.
Try not to overthink this right now.

#1 is a full charge.
Anything less will send you down a wrong path.

 

Thanks Mike, thinking about getting a recharge tomorrow before I let my buddy look at it. Here's a short clip of the compressor.

Compressor: http://youtu.be/Kvz51N29HLw

 

I don't see an issue with pulleys etc.
Make sure they put dye in it.

 

Ten four, will keep you updated. Thanks.

 

Brought it to my buddy, we think we have pin pointed it to the pressure switch in the evaporator. We hooked a power tester to it and you could see when it would kick in and engage the clutch on the compressor. Also would explain the weird ticking noise in the blower motor. Must have been actually the evaporator going.

 

Ok folks... At a stand still and need help. Tore into the dash this afternoon and dropped the evaporator after draining the system. The coils were slammed pack with debry! Cleaned the best I could, replaced the pressure switch and buttoned her back up. Clutch still sporadically engaging on and off with no consistency, regardless of temp or pressure. Started checking wires and harness... Finally pinpointed the problem!

The AC amplifier pack has a computer board in it. Pulled the board and tested connections between posts and all were good expect the relay! Put a test light on it and cranked it up, you could see the inconsistency in the signals it was sending.

So with this being said, I've researched online and the big auction website with no luck yet. So if anyone has a website or link to a 1995 taco AC amplifier or has a parts truck they want to just pull the board out I'd MUCH appreciate it! I found one online that sold awhile back for $40-$50, I''ll be happy to pay for it. It's VERY easy to remove with out taking anything apart, you just look under the glove box. I have a part number if needed. So anyone think they can help me out? Thanks guys.

 

One last update, a Google search of what I'm assuming is the part number (Orange and white sticker) of 88650-0410, comes up ac assembly/cooler stabilizer. They only provide vague parts schematics without actual part photos so not sure if it's what I need? Guess I'll try the dealer worst case. Thanks guys.

 

TTT for the night.

 

Just waiting on these tests you did to confirm your diag.
Your terminology may be misleading.
The sensor in the evap with a probe that sticks between the fins is not a pressure sensor. It's a temp sensor. Pressure sensor is in the high side line or in the "h" valve. Been while since I had one this old in front of me.
Have seen the ac amp give a system fits but I can only sit back and assume the sensors were checked correctly and the pressures were good to activate the system.
The parts view really stink and that is the correct set of numbers you posted.

 

Hey Mike thanks for the feedback. I did not know that was the sensor switch, based off the Hanes manual I have I thought that was the correct terminology. I also searched that term online and found the part I did. Regardless it didn't matter for both parts were good. Also the switch I replaced wasn't actually in the fins, if I'm thinking correctly I know what your referring too. The current part I'm looking for is just on the bottom of the evaporator housing. I've yet to call the dealer, but will Tomorrow. Thanks for all your help.

 

Sure thing. Just let us know what it took to fix it.

 

I know it's been a while since I've done this for a living, but my money is still on low freon. When you are charging it, does the compressor stay on any longer than originally? If so, than it is low on freon. If not, the next pplace I would look is the thermostatic expansion valve (there are two different names, but both basically do the same thing). This cave allows freon to pass from one side of the system to the other. If it gets contaminated, it doesn't let the fluid pass, essentially letting the compressor think you are low on freon. If you find this valve to be bad, you need to do a full evacuation and recharge as the rest of the system will become contaminated when replacing it.