AC seems to not blow when stopped but begin to blow when accelerating. (1 Viewer)

[aonis]

Hi there,

I'm new to the FJ62 world but am happy to be here! As mentioned above, the ac seems to work decently in my car but as I said it really only begins to blow hard when I accelerate the vehicle. Is this normal? It seems I have to play with the switches a bit to get things going but I might be doing something wrong. Any guidance would be a big help!

 

[Michael Hanson]

Hi, Fan bushings are wearing down. Or alternator is . Mike

 

[g-man]

Things that cause voltage loss at the blower fan: the heater CB...they get old and don't really hold until 30amps. Current has to run thru them and they get weak. This is top right of the fuse panel. These can and will trip with the fan and AC on high if they get too worn. Pull and replace with a 30amp inline fuse and some flat spade terminals.

The blower resistor housed above the accelerator pedal and toward the middle of the dash. Unplug the harness and unscrew it. They get rusty because they live inside the vent. Tiny coiled wires to vary the resistance at different fan speeds. Aftermarket resistors are available.

Lastly the contacts on the slide switch at the instrument panel itself can get tarnished but pulling it to clean the tarnish is hardly worth the gain.

 

[g-man]

We are talking about the blower fan and not the ac compressor right? The AC compressor has an amplifier with an adjustable dial that tells the compressor to cut off when the rpms drop to 600-700. So the compressor is not running at while the engine is at idle.

 

[aonis]

The air comes out cold when it actually blows, so I don't think it's the compressor. I believe it's the blower. Does that make sense?

I think I'll start investigating the voltage issue. If it's the alternator, are we talking about something difficult to replace?

 

[lcwizard]

step on the throttle in neutral. If air flow increases then it's voltage. If air flow is the same but just gets colder it's ac amplifier adjustment
our head pressures getting to high in the compressor which could be caused by a weak cooling system like bad fan clutch or general
maintenance needed in the AC system

 

[aonis]

Thanks everyone, this is very informative. I'll do some tests after work and see if i can determine where the issue is coming from.

 

[aonis]

Ok so I do have a small update, after some testing.

Basically I can get cold air coming through my blowers only if the vent setting is set to let air in from outside vs circulating air and the car is moving. Would that mean that the AC compressor is making cold air but the blower simply isn't working? I'm going to check the fuses and check out the blower resistor but that's my update so far.

 

[Zjohnsonua]

Turn the key to ON, but don't start the truck. Then move the fan speed selector through the positions. With the engine off you should clearly hear the fan come on and then speed up or slow down.

Your description sounds like your fan isn't working at all though. If this is the case then others have given sound advice above on the components that need investigation.

Lucky you for needed AC right now! We're freezing to death and working to get heaters hotter.

Best of luck on sorting this one out.

 

[aonis]

Will check that tonight, thank you! And yes, after living in the Northeast for 15yrs I really feel for what everyone is going through with this winter vortex up North!

 

[g-man]

You can check the fan motor with the a/c off also. Just push the blue ac button off. And work the fan positions.

 

[Dr. John]

As a baseline, you should check the blower motor and fan for debris. 3, easy to get to screws, hold the motor and fan in place. You may find that your only problem is leaves, etc. that have been sucked into the fan and plenum. I pulled out almost a 5-gallon bucket full of leaves and pine straw from the fan box and the plenum accessed from the 3 plates on the engine side firewall. Only difficult part was r/r of the wiper motor. Blows air like new now.

 

[aonis]

As a baseline, you should check the blower motor and fan for debris. 3, easy to get to screws, hold the motor and fan in place. You may find that your only problem is leaves, etc. that have been sucked into the fan and plenum. I pulled out almost a 5-gallon bucket full of leaves and pine straw from the fan box and the plenum accessed from the 3 plates on the engine side firewall. Only difficult part was r/r of the wiper motor. Blows air like new now.

Do you know of any tutorials online for this? Either print or video?

 

[g-man]

The fan motor is below the dash under the glove box. It will look like this:

Put your hands on it and feel the vibrations to know its running. Like mentioned above you can run it with the key in the acc position and the motor off. And like mentioned above, 3 screws and unplug the wires from the side. Drop it down and clean up the vent space. Inspect the contacts for corrosion etc.

One banana job.

 

[g-man]

 

[aonis]

you guys are awesome, thank you

 

[aonis]

Well I solved the problem! But I also feel like an idiot or as g-man put it, I deserve a banana

When I took apart the blower housing I basically discovered that the electrical source to the fan was simply loose! Which explains why it worked sometimes and not others. I put it back firmly in place and it's blowing like new!

Now onto my other project, improving my power windows

 

[g-man]

one banana for you!