fixing air con

[92gtst]

Ok my air con controls work, I can pick a temperature, how/where I want the air to blow (feet, face, windscreen etc), all the bits (acuators) that open and close pathways for air to travel, rear defogger works... The only problem is no air blows at all hot or cold....

I've spent the last few hours in the dark too... trying to diagnose the problem with the a/c or even better get it working.... I am so damn frustrated I could scream!!!!!!!!!!

So lets review what I've tried.... not in order...

1. checked all fuses - fuses good
2. rem ove blower motor and test with power direct from battery - blower motor works!
3. tested the voltage at the blower motor plug - got about 12v.... I presume that means the plug can power the blower...
4. tested heater relay - checked magnetic switch operation, and continuity of appropriate terminals... it's good... I can also hear it working when the blower is turned on,,,
5. also measured voltage between terminal HR of air con control assembly (a/c ecu) and body ground voltage correct.
6. checked voltage between terminals IG+ and E of a/c ecu - correct
7, checked voltage between terminal acc of a/c ecu and body ground - good
8. I pulled the A/C magnetic relay from relay box under the hood.... it appeared to work and have continuity, but I don't think the switch was engaging,,,, If I took my pliers i could close the switch (I think that completes a cicuit) and it would make a noise somewhere near where I think the compressor is....
9. I had a couple of spare A/C relays so I swapped them to see if there was any difference but it's the same with them all.... it seems the switch stays open when installed in the relay box... -IS THIS SIGNIFICANT???
10. I had the blower motor connected to it's power plug and hanging / sitting on the car floor...
I turned the air con on (blower on) with ignition to on, but car not running... nothing, I turned the ignition and the blower started working!!!!!!!

So i thought I've won problem sorted, put the blower motor back in it's place, put everything else back together. Try out the air con and the blower motor does nothing.... still no frickin air blowing out of the piece of crap **** fuc#$#$% thing....

So my question is could the compressor stop the blower from blowing air???

What exactly does the A/c relay in the relay box under the hood do??? does it matter if the switch doesn;t close (like when you power a relay)?????

The fuse by the heater relay looked ok and has continuity....

I was unable to investigate the compressor at all as it was too dark...

I don;t understand why the blower motor would work suddenly and unexpectedly when I had the blower on and turned the ignition on, and then it don't work anymore when I put everything back together...??????????????

Help please!!!!!!!!!!!!! I can't take much more, I fell like making a sledge hammer my next tool in dealing with the problem....
Where do I look next??? I'm so damn pissed off and angry and I can't take much more of this....
I really can't afford to pay someone to fix it, I want my air con working this is really starting to aggravate me.............

[phoenix]

You seem to be talking about separate systems. From my experience the fan/blower & air director mechanism operates all of the airflow, while the heater and A/C systems just have radiators that sit in the airflow to effect changes in the temperature and/or remove moisture.

I would just concentrate on the fan/blower. Putting events in order:

- Fan didn't go at all when everything was assembled, so you took stuff apart
- Fan did go when separate power is applied
- There seems to be power to the fan plug
- Fan went when it was plugged in and stuff was disassembled
- Fan no longer worked when plugged in and reassembled

It almost sounds like there is a loose connection when it's in an assembled state. When the fan did work (plugged in but disassembled) did the different fan speeds work properly?

[JZCrazy]

Are these A/C problems on your ES300?

If so you might be able to run diagnostics on the A/C system and pick up an error code.

[Crucible]

Im not sure what car you have but Resistor packs that control speed are quite common to fry and cause an open circuit (no ground) but generally you will get one or two speeds that will work. So you do not have any blower function on all settings?

It sounds from what you have checked the blower motor is faulty/intermittent.

Try this, if you can get to the blower plug in place check which one has power ( plug disconnected) plug it back in and run a jumper wire to earth on the other wire/termanal. If no go you have good + and - so motor is stuffed. If it cycles give the motor a few taps if it drops off pulses etc then motor aswell. If cycles and all good the prob is on the fan control side, not providing an earth.

It is also important to check voltage at fan while WORKING to rule out voltage drop.

[whynot]

Try putting a test lamp on the fan plug. You may have voltage there but no current to run the fan. If that's the case I would be looking at the speed control module.

[Crucible]

Plugged in it will have 12v on both pins if its a module/resistor pack faulty not providing an earth (open). Can also unplug and put test light across both pins on plug to see if it has power and earth.

[92gtst]

Ok I pulled it apart again rechecked voltage, continuity etc...

Plugged it into it's power plug nothing.... Fan setting high

For some reason I decided to spin the rotor and that got it going! I can put it into it's housing and air blows as it should...

Anyway with it running at full speed if I turn it down to medium or low it stops working... If I turn it back to high it will carry on spinning as long as the rotor hadn't fully stopped...

So the only way to get it to work is by giving it a push start!

Yes this is on my Windom / ES300....

Hot & cold air seem to work... The stupid blower just can't start spinning on it's own, and won't spin on anything but high when given a push start...

So is it the blower motor??? or perhaps a resistor???

[92gtst]

Are these A/C problems on your ES300?

If so you might be able to run diagnostics on the A/C system and pick up an error code.

I ran diagnostics a while back and got codes 21 & 23.

21 is the solar sensor 23 is either "open in pressure sensor circuit" or "abnormal refrigerant pressure".

I don't think either is the cause of the problem with the blower motor...

[Crucible]

So you need to prove the blower motor is ok. But you need to check for voltage drop at the plug aswell to make sure the circuit is ok UNDER LOAD!

Like I said before, with the plug CONNECTED, run a seperate ground from plug (back probing with a split pin or whatever).

When it runs check what the voltage is at the powerside backprobing the plug. This shows available voltage under load and eliminates corrosion, resistance, crook relay n the powerside. If you have 12v while running the power circuit is good, and the problem is on the earth side of the motor.

Doing the above eliminates, power supply problem and motor being faulty which only leaves a bad earth. The fan control provides an earth so can only mean its faulty.

Reason I suggest checking available v when its working is u can have 10 resistors in series on a power feed but if you check with multmeter UNPLUGGED you will still have 12v. No current flow, No voltage drop!!!

[matt dunn]

The fan motor is worn out, you will need to fix it by fitting new brushes or replace the whole thing.

[Crucible]

I say motor aswell.

Real life..2min to diagnose. Trying to explain on the internet..2 hours

[92gtst]

The motor spun just fine with 12v direct from the battery.....

Anyway I got pissed off with it and dealt to it with a hammer, so that blower motor will no longer be a problem

I grabbed a new one from pick a part this morning, it works with power direct from the battery (but so did the last one)

I'll put it in later and see what happens....

Why does the motor work with power direct from the battery, but requires a push start when plugged in???

I'll try the suggested additional diagnostic measures if the problem is the same with the replacement blower motor.... I'm sort of thinking now that I'm going to have the same problem tho.... I probably shouldn't have wrecked the original blower motor, but who knows... fingers crossed replacement sorts it out...

I've read a resistor is often the problem you can only use one speed setting...

[Lloyd]

It'll go fine because the brushes are pretty much toast. They wear and get dirty, so sit in a spot every so often where there isn't enough current flowing to get the fan to move. As soon as you turn it it'll make better contact and continue spinning. The same reason starter motors only sometimes go when they're worn out, kicking a fuel tank to get a work fuel pump to kick over etc.

The fan resistor is used to drop power to the blower motor when you want a slower speed. When you put the fan on full power then you complete bypass the resistor. If that is faulty then with a full functioning system you'll only have the fan working on full speed.

[92gtst]

yeah I think the brushes had actually come out of place... they were still connected but sitting funny inside the blower... looked like they'd seen better days

[Bling]

Was that before or after you adjusted it with the hammer?