vegascoug

1990 4Runner 4WD, V6 3.0 4 Door, Auto Trans

So why is it that every time my wife drives my truck, something goes wrong? Well, let me rephrase that, every time something goes wrong, my wife is driving. So asking diagnostic questions is about as useful as throwing darts at your feet.

So she got home and told me the power steering was out. My dad and I took a look (he's the mech) to see if the belt came off. Sure enough, it was off. The reason it was off was because the smaller belt that controls the A/C pump got damaged and thrown off, which took the PS belt off. The serpentine belt was still in good shape (old but on)...so I got 3 new belts to replace them all.

After discovering how these 3 belts go on, and finding all the extremely hard to reach nuts that loosen pulleys so you can put new belts on...everything seemed great. All three belts are spinning, no pulleys are locked up, power steering works fantastic, etc. However no A/C. The light comes on, fan blows, but no cold air. I let it run for a while and still no A/C.

Any ideas what I can check for...I hear a high pitched whistle or ringing when the A/C comes on...and my dad suggested that maybe the clutch isn't engaging...maybe a wire was knocked loose when that belt flew off. I am not the mech, I come to you guys on here for expert help when I need it, and I always find it. So if someone can at least point me in the direction of the needle I'm looking for, my day might not be spent entirely covered in hay.

Thanks
Mike

eric-the-red

You should be able to see if the clutch is engaging. With the engine running and A/C off the pulley and belt will be spinning, but the clutch should be still. With the A/C on the clutch should start spinning. There is only one wire controlling the clutch, should be black/white. Check and see if that's loose. Another possibility is a siezed compressor, which may have been the cause of the belt breaking originally.

vegascoug

That's what I was afraid of...has to be a reason the belt fried in the first place. I'll check it out...hopefully it's just a bad or loose wire...I don't want to replace the compressor.

Thanks for the feedback!

Kutter

You should be able to reach down (with the engine not running) and turn by hand the front part of the AC compressor clutch. If you cannot turn it by hand then your compressor could be locked up.

If it turns by hand then you can check its operation by opening the small grey plug with the single wire going into the compressor. Put 12 volts from the battery positive terminal. This should cause the AC compressor clutch to actuate and close with a clicking sound.

If your freon level is too low then the compressor will not turn on. This is a normal function to protect your compressor from operating without adequate internal lubrication.

vegascoug

Well here's where I'm at, so forgive me because I'm about to sound reallys stupid to some. Before I put the belts on, every pulley (sans the one on the front of the engine that the fant bolts to) spun freely. The lower of the 3 belts, the one that connects to the air pulley, has three it connects to. The main one on the front of the engine, the one of the front of the A/C, and a smaller one near the bottom of the engine. That smaller one is the one with the tensioner on it to tighten the belt. All three spin wheather or not the A/C is on in the truck or off. I have turned the A/C on and off and can't tell a difference. I had my wife sit in the truck and turn it off and on and I cannot see anything moving, hear anything clicking, etc.

What exactly is supposed to happen when the A/C clutch actuates? What am I looking for exactly? (this is the stupid part). I am not a mech, just like to work on my own truck and my dad who was a mech is in Vegas, so I'm SOL at the moment.

Could it be a fuse problem? I know there are a couple fuses that control this system, located very conveniently behind the Glove Box (nice idea Yota). Would my A/C light turn on if there was a blown fuse? I was just thinking if my wife had this on and the belt was off, could that have blown the fuse? My freon has always been fine, at least my A/C was always bitter cold and got that way in seconds, so I don't think it was low.

I'll start with the clutch issue if someone doesn't mind telling me what I am looking for, and then move forward.

EDIT: Called my dad, explained to me what the clutch was. It spins freely without the engine on, but I don't think it's engaging. So the good news is apparently it's not locked up/frozen, but now to figure out why it's not coming on.

Thanks,
Mike

JEBSR5

Check this link for compressor picture.
http://www.2carpros.com/topics/ac.htm
Obviously this isn't your compressor but the picture is for illustration. Note the ribbed pulley. That spins all the time whether AC compressor clutch engaged or not. In the center of that that has a bolt through the ceter is the clutch, when engaged it spins also. Sounds like yours is not.

vegascoug

Thanks, great picture

JEBSR5

Did that clear up what to look for as far as motion?

See where you edited your post and figured it out. Check to see if the wiring is still hooked up, manual says not to apply direct current to lead. My guess is it may blow you AC amplifier. If you can trouble shoot via an online manual that could help. First thing in my manual is it says to check IGN fuse, not sure why.

Does the inside heater fan, etc work OK?

Online FSM, goto AC, troubleshooting. This is for 93, but it's the same for 90-95.
http://personal.utulsa.edu/~nathan-buchanan/93fsm/

vegascoug

Yes that helps, now I know exactly what to look for and what the problem is, just don't know the cause yet.

That clutch doesn't engage. It spins freely (you can even hear the pistons inside it moving) so that part is working. However it won't spin with or without the A/C on. I don't hear a "click" either.

My dad suggested turning the A/C on and the key on, but engine off, and then taking that gray plug that comes from the black wire that runs off the compressor and unplug and plug that in, he said I should hear the clutch "click" when it's getting the signal to engage/disengage as I add and remove power to it. Nothing happens. I've tried taking out the fuses, and they look okay. Without the big one (resistor?) in I hear a click when I turn on the fan, but nothing happens, when it's in the fan turns on, but still no A/C, but that tells me that the fuse is okay because it kills the fan also with it out. If it were bad, the fan wouldn't run with it in either. There is one other fuse according to the manual that runs the A/C, and it looks okay, haven't tried replacing it yet though.

I am going to get a test light and see if those two wires (black and white) are getting power, if not than my problem is before the compressor. If they are getting/giving power, than my issue is with the compressor itself. It's not frozen, but I suppose it could be dead. I don't know enough about Toyotas or A/C compressors in general to answer that.

Mike