AC/Blower issues

[swensonator]

Hey everyone:

So, my AC (compressor) and blower have both stopped working on my 98 camry and I'm looking for suggestions on how to diagnose the problem.

Searching the forums, I saw people talking about the blower resistor being an issue in the instance where some, but not all, of the blower speeds were working. In my case the blower isn't working at all, so I don't think that is the problem, but I can pull out the resistor and throw in a new one if someone with more experience thinks it is worth it.

My other thought is that maybe I've got 2 bad relays, the Heater and the MG Clutch. I'm not sure how to diagnose whether that is the problem, though. I have an Am/Volt meter, but some of the things I've read talk about connecting the relay to the battery with fused wire, which I don't have. Any other safe/simple way to check the relays?

The other clue is that the environmental panel doesn't seem to work either. The fuses are all good, but the AC light doesn't come on anymore, the defroster light doesn't turn on (the button also doesn't click and stay depressed when I try to turn it on), and the vent position doesn't change (though this may only happen if the blower is functional).

Any suggestions on where to start?

thanks.

[Mister_Perkins]

Your blower motor is probably bad. Check for voltage to the blower motor first. Make sure theres 12v+ If theres not, it is probably a Relay.

Most of the time if the Resistor is going bad, depending on the model of car it will have HIGH Speed or OFF. That's an indication of a burnt board. Some other models if the resistor goes bad the motor will not work at all.

If you have 12V to the blower motor though, its more than likely just a faulty blower motor... It does happen.

[rusty9]

well since his ENTIRE hvac system doesnt work, id suggest checking the main heater fuse which i believe is under the hood, then check all the other fuses first.

[Mister_Perkins]

Yeah its easy to check fuses, and also easy to check for voltage. Just about as easy either way. To check for voltage, you just unplug the Blower harness, probe the pin, ground it. Lights up, you have voltage. Not light up, then wire or fuse is bad.

but yes rusty9, you are correct.. check the fuses first, then move to checking the blower motor for power

[swensonator]

I checked the voltage to the blower this morning and got nothing. So no voltage to the blower means I step back to the fuses/relays, right? There isn't actually a "fuse" for the HVAC system as a whole, is there? Aren't the fuses built into the relays for those high voltage components? The only fuse that seemed to be directly connected to the HVAC system was the AC fuse, but all it controls is the backlight for when it is turned on.

So, assuming the heater fuses are built into the Heater relay, how do I go about checking a relay?

Thanks for you help.

[Mister_Perkins]

Originally Posted by swensonator

I checked the voltage to the blower this morning and got nothing. So no voltage to the blower means I step back to the fuses/relays, right? There isn't actually a "fuse" for the HVAC system as a whole, is there? Aren't the fuses built into the relays for those high voltage components? The only fuse that seemed to be directly connected to the HVAC system was the AC fuse, but all it controls is the backlight for when it is turned on.

So, assuming the heater fuses are built into the Heater relay, how do I go about checking a relay?

Thanks for you help.

There are two things you can check..

You have a 40A Heater fuse under the hood, you also have a Heater Relay. One side should have continuity (Pins 3 and 1) and the other side (Pins 4 and 5) should not have continuity. (Pins 4 and 2) should also have continuity when its not engaged.

If the 40A Fuse is good, and the relay is good ... Pull your Heater controls out, and test where the harness connects to it. every pin should have continuity. (If it has all electronic t –2–3–5–6 will have continuity) If it has a lever for inside/outside air (1–2–3–6 will have continuity).

Here are some pictures to help out:

[swensonator]

Ok, so the 50A heater fuse looks good. I pulled off the relay and got no continuity between what you labeled pins 1 and 3. I stopped by NAPA on the way home and picked up a new blower relay and got no continuity between 1 and 3 either. However I do get continuity between pins 4 and 5 (80 ohms) and continuity between pins 3 and 2 (0 ohms), using the pin labeling from your schematic. I checked my original relay and got the same result, so I'm wondering if your schematic is mislabeled.

Assuming the relay is good (since it matches the behavior of the new relay) and the fuse is good, I guess I'll have to move on to checking the HVAC head unit. I'll try and get that done this weekend and let you know what I find.

Thanks.

EDIT: OK, I just had some success. If I put in a jumper cable from the battery + to pin 5 (on your schematic) the blower turns on, which leads me to believe that I just have a loose connection or a short in the wire from battery + (ground was fine, it didn't need a jumper cable). However, when I tried doing the same thing with the MG Clutch relay (connected both + and -) the compressor didn't turn on. Any advice on how to diagnose the remaining portion of my problem?

[Mister_Perkins]

Yeah, well it doesn't help that my Schematics are for a 92-96 either. In 97-01 it may have changed.

Since when you apply voltage to the switched side and it turns on, that leads me to believe that the wire that "switches" the voltage either has a bad ground, or is faulty.

It could be something as simple as the Blower Resistor is bad, not sending the switch signal.

To turn the AC Compressor on manually, you need to jump the AC Relay on the Switched side
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[swensonator]

Well, I finally got the blower working again, but my wife was getting impatient and given my lack of experience with the AC system, I decided to take the car into the shop and have it looked at.

Long story short, the condenser is leaking and I need a new condenser and drier/accumulator. The shop wants $806 for the parts and labor. Given the value of the car, I don't think the repair is necessarily worth it at that cost. Looking online, I can get a condenser and drier for much cheaper using aftermarket parts. Is this a repair that I can do myself? I did a search on the forums and didn't see too many people mentioning replacing a condenser, so I'm not sure how difficult it would be. (I do all my own regular maintenance, like fluid changes, and I've changed the thermostat and a couple belts, but I'm by no means an expert or highly experienced.) If I can do the work myself for ~$200 and spend a Saturday afternoon doing it, then it would probably be worthwhile.

Any input?

Thanks.

[Stillrunning]

Originally Posted by swensonator

Long story short, the condenser is leaking and I need a new condenser and drier/accumulator. The shop wants $806 for the parts and labor. Any input?

Did the shop say your A/C & blower was not working because the system lacked pressure and the pressure switch was not allowing the system to turn on?

[swensonator]

That's actually part of the 'Long story short'. I took the car into the shop last week and the pressure was low, so the pressure switch was inhibiting the system from turning on. They filled the system and added UV dye. 72 hrs. later the AC stopped working again. That's when I took it in for a 2nd time and they were able to see that the condenser was leaking. At that point they came back to me with the potential $806 bill. I told I would think about it and get back to them. They gave me the part numbers of what I needed and I looked them up online.

I found this on amazon:

http://www.amazon.com/Denso-477-0513-Condenser/dp/B000C5YFVI/ref=au_pf_pfg_s?ie=UTF8&Model=Camry|1011&n=15684181&s=automotive&Make=Toyota|76&Year=1998|1998&newCar=1&carId=001

http://www.amazon.com/Denso-477-0513-Condenser/dp/B000C5YFVI/ref=au_pf_pfg_s?ie=UTF8&Model=Camry|1011&n=15684181&s=automotive&Make=Toyota|76&Year=1998|1998&newCar=1&carId=001

And the drier is available from various sources for <$20. So I'm curious as to whether this is something I could do on my own?

Thanks.

[carsrus]

The condensor is pretty straightforward job. You need to remove the radiator though. All in all its pretty simple.

BUT, the A/C system must have no pressure. If you loosen the line and there's refrigerant there will be an enormous explosion of gas. Ive seen it happen before. Very, very dangerous.

Also after the new condenser and drier is installed the whole system much be evacuated and recharged which will run at least 70$. If the A/C compressor isnt kicking it there probably isn't much pressure left, but, if you want to do the repair yourself I would left the system air out for a couple weeks.

Good A/C specialists are really hard to come by thats why the price is so high. Its not a hard job but its something most mechanics cannot do properly since they do not have the $$$ A/C evac/refill tools.

[swensonator]

Thanks for your input. I don't mind a $70 cost to evacuate and recharge, that I can definitely manage, if I do the rest myself. Is there any way I can speed up the time it takes for the system to de-pressurize (without resulting in an explosive decompression)? I might be hard pressed to convince my wife to left it sit 'for a couple weeks'. For instance, could I jump the pins on the pressure switch and force the compressor on? I assume that would increase the 'high' side pressure and increase the rate of the leak. Or is that just bad for the compressor?

[carsrus]

Originally Posted by swensonator

Thanks for your input. I don't mind a $70 cost to evacuate and recharge, that I can definitely manage. Anyway I can speed up the time it takes for the system to de-pressurize (without resulting in an explosive decompression)? I might be hard pressed to convince my wife to left it sit 'for a couple weeks'.

Dont tell the green freak this, but if you take a charge hose (the one with the can on one end and the low pressure side connector on the other) Connect it to the low pressure side and without a can slowly open the valve. There probally isnt much left, but wear good gloves and layers. Instant freeze burns if it gets on you. Safety is key.

Yeah Ill probally get flamed for this but the amount of r134a that leaks out into the atmosphere is huge and this method isn't gonna melt the polar ice caps.

[Mister_Perkins]

Originally Posted by carsrus

Dont tell the green freak this, but if you take a charge hose (the one with the can on one end and the low pressure side connector on the other) Connect it to the low pressure side and without a can slowly open the valve. There probally isnt much left, but wear good gloves and layers. Instant freeze burns if it gets on you. Safety is key.

Yeah Ill probally get flamed for this but the amount of r134a that leaks out into the atmosphere is huge and this method isn't gonna melt the polar ice caps.

The concept of changing the parts out is straight forward. You need O-Rings, the parts, a Vacuum pump, manifold gauges, R134A, an Empty tank to collect the Freon.

The empty tank is optional, but recommended. If you have a nosy neighbor and they see what your doing and record you and turn it in to the authorities you can get fined big bucks.

Make absolutely certain that you replace the O Rings in the lines you disconnect. Also, when Re-charging I recommend using a florescent Dye to notice any leaks through the whole process.

Its a recommended practice that when you replace the Condensor, you replace the Dryer / Accumulator as well. One should not be changed without the other.

It's very Do-able for the DIY Mechanic though. It's a very straight forward installation.

Good Luck