Tryna get my friend's A/C going on a 1991 Toyota "suburban" wagon. Like a corolla wagon?
Think it's electrical, and would like to explore that first. The A/C stopped working after getting mildly rear ended.
Would like to check fuses first, if that makes sense. Looked at the fuse panel by the driver's left leg, and it said on the cover "heater-A/C breakers by assist kick plate". What/where is an "assist kick plate"?
Horn does not work, possibly a loose wire--there is a dangling wire, can't see where it goes. Mention this because this loose wire is also right next to what looks like the A/C condenser, and possibly may not be for the horn. Also don't see a horn fuse. I see a horn relay in a fuse block under the hood, but no fuse.
Am still looking for the low pressure switch, mentioned to me in another thread, to jump out. How do I recognize this? . The A/C compressor looks to be under the alternator, w/ one wire (that I can see) going to it. Sort of loose, think I snugged it in. Don't see any other wires, looking from the top, hoping to find the wires that activate the A/C clutch.
Both radiator fans click on/off, as car idles in hot weather.
If I could SEE where shit was, I'd have a better shot at sleuthing the problem.
Depending on your vehicle (sounds like you don't know what you are working on...) the A/C clutch fuse and MG relay may be behind the passenger side kickplate under the glovebox area. It should be a 7.5 or 10amp fuse. There are plenty of other fuses in this system however.
There are fuses in the engine compartment box AND in the box up above the driver's knee bolster or left kickpanel area. Look both places.
The wire near the condenser should not be A/C related on a Corolla- sortof-kindof. It is likely a broken wire to the horn. The important A/C switches and wiring underhood for Corolla-sortofs are in the high pressure line near the firewall where it goes into the evaporator. I have seen broken wiring in this area on several different bodystyles of the early 1990's era Corolla. Broken wire(s) here can cause constant A/C fan operation or no A/C depending on which circuit is open.
There's a two wire "dual pressure switch" and a high pressure fan switch on the high line (depending on your vehicle), and it's where I specified above on old Corollas.
There is very little of the A/C electrical system on Corollas that is hard to see. You may be looking to make it harder. Investigate a wiring diagram before proceeding if you want to make things easier.
Where might I find shematics? Someone mentioned the Mitchell series at a library. Mebbe the service dept would photocopy sumpn for me? Anywhere else?
Is the compressor below the alternator? Are any wires going to the compressor necessarily for the clutch?
How do I tell high pressure side from low pressure? And this low pressure switch: It would be by the firewall? With two wires?
There is one set of fuses by the drivers' left leg. Is that the only set on the drivers side? I'll check under the glove box again, but I did look, and nothing was clear, like the cover on the driver's side.
The MG thing is under the hood, clearly labeled on a fuse block. What does MG stand for? Is that what they mean by heater/A/C circuit breaker, or is this elsewhere?
I'm assuming that if something just goes out after a fender bender, it's electrical. Reasonable?
Besides buying the info, are those two free resources not enough? You can even get the exact factory info back to 1990 at
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.com for $10 per day. Print off what you need in .pdf form but it helps to have Acrobat Reader 8.x.
Yes. THE wire is for the clutch. No other "compressor" wires on Corolla-esque cars.
Only for the purpose of identifying where the switches are, the high pressure line is smaller diameter. NOW, if you know that little about A/C, please don't even think about servicing any refrigerant holding parts (don't unbolt/unscrew anything at the compressor, condenser, drier, evaporator, at any lines or on any lines). Don't touch it. Don't even look at it. Just enjoy the sustain.
As previously stated, it is called a dual pressure switch and yes and yes.
Probably.
BEHIND THE RIGHT SIDE KICK PANEL.
MG is Toyota's term for A/C clutch relay.
As reasonable as assuming that a component was jarred hard enough to crack and lose all refrigerant.
------------------------------------------ That's as far as I go without an exact make, model, year, and engine. I can help -given that info- during normal work hours.
Besides buying the info, are those two free resources not enough? You can even get the exact factory info back to 1990 at
formatting link
for $10 per day. Print off what you need in .pdf form but it helps to have Acrobat Reader 8.x.
Yes. THE wire is for the clutch. No other "compressor" wires on Corolla-esque cars.
Only for the purpose of identifying where the switches are, the high pressure line is smaller diameter. NOW, if you know that little about A/C, please don't even think about servicing any refrigerant holding parts (don't unbolt/unscrew anything at the compressor, condenser, drier, evaporator, at any lines or on any lines). Don't touch it. Don't even look at it. Just enjoy the sustain.
As previously stated, it is called a dual pressure switch and yes and yes.
Probably.
BEHIND THE RIGHT SIDE KICK PANEL.
MG is Toyota's term for A/C clutch relay.
As reasonable as assuming that a component was jarred hard enough to crack and lose all refrigerant.
------------------------------------------ That's as far as I go without an exact make, model, year, and engine. I can help -given that info- during normal work hours.
-----------------
Bless you. I'll try and get this info, but hopefully I'll make some headway with the above.
What I'm going to do first is pull that wire from the compressor, and see if it is energized, with the car (presumably) calling for A/C.
If it IS energized (with no jump on the pressure switch), then I know I have either a bad clutch or a bad compressor.
If it's not energized, then I know the problem is further upstream someplace.
If I then find the pressure switch, jump it out, and this wire becomes energized, I'll have two choices: a) bad pressure switch, or b) loss of refrigerant, I'll be able to distinguish which by seeing if cold air blows or not.
If I jump the pressure switch, and this wire is not energized, then presumably there is still an electrical problem further upstream, possibly the A/C switch itself on the dash. That's a pita.... Hopefully it'll be a fuse or that MG relay. And,
I could always run a jumper from the battery to the clutch, see what happens.
Good so far?
A lot of this depends on being able to tell if the compressor is actually engaged or not! I can tell if I hear it go on and off, but how would I tell the state if it's *always* on, or always off?? Sorta not easy to tell (for an amateur) with all the engine noise, etc.
I would think that listing basic car designations would be the easiest part of this whole diagnostic procedure.
Sound diagnostic strategy, yes.
Look at the clutch hub with a flashlight while the engine is running. It's easy to see, right under the alternator, it has its own belt on Corollas. You will see with a strong flashlight whether or not the clutch is turning.
Look at the frontmost, rightmost, lowest possible spot in the passenger footwell. There is a small plastic panel in that area that covers up some wiring, relays, etc. Example: if you were to 'kick' your right foot to the right while seated in the passenger seat you would hit the kick plate (unless you are Emmanuel Lewis or Billy Barty).
OK-- It's going to be a cupla days or so 'til I can get to this car, when I'll get the info and start this sleuthing process. God-god willing, if I run a jump to the compressor, I'll see dat hub turn, and feel some cold air blow!
I'll then have option of sleuthing the true culprit down, or just keeping the jump and running a switch inside to the cabin area. It is, after all, a 1991 car! But, it runs sweet.
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