yea there's quite a bit of these threads lately and probably even more to come but anyhow.

When you change the temp from cold to hot you should at least feel a slight shift in air preassure or hear something right?
Cause pretty much yesterday while in the rain my heater suddendly decides to stop working and the inside of my car started fogging, now all the switches work including AC just that there's no heat coming out and the air temp's the same weather on hot or cold so I'm pretty sure the logicon's still working. So I'm guessing it could be the heater core? Anyone know how you can tell asides from taking it apart?

 

I'll probably take this to a mechanic sometime, but I'd like to take a look at it first so anyone?

 

first warm up the vehicle then feel the hoses going into the heater core, if one is hot and the other is not, the heater core is plugged. If both of the hoses are hot its functioning properly (you'll need a pyrometer to try to see if its partially plugged I suppose). The change in pressure and sound is the closing of the temperature blend door, the door that directs air to the heater core (I'm pretty sure) either way if that doesnt move, it wont direct air to adjust temperature, the door can be physically broken to where the blend door actuator cannot turn it, so you have to visually inspect it (by taking the actuator off).

The best way to determine the problem if it is the door itself or the actuator is to simply take the actuator off, turn the key on and move the heater ****, if the actuator turns (they turn really slow, with lots of torque, which can actually break the door) it must be the door itself, either broken or stuck on something. If the actuator does not turn you will have to find the circuit at fault and repair it (get out the DVOM and wiring diagram) or it could be the heater control slider. Sorry I cant direct you to locations of the blend door or actuator since I've never worked on an rx7, I just recently bought mine. but start by looking under the dash probably towards the center, you might have to take out the radio, but I could be wrong. I think thats the set up, anyway hope that give you some direction

 

thanks, looks bit hard but that could just be cause of the time, but I'll try that and look into it in the morning.

 

i'm havin the same issues... The car was working fine and all of a sudden the air stopped blowing out... Ughhhh

 

If air isn't blowing at all it's probably the fan or fan control on the logicon.
If air is blowing but the temperature doesn't change then it's either the logicon, air mix motor or the core.

You can test the core like fc3sGTUs said. You can check the logicon by swapping in a good one and testing. You can check the air mix motor by turning the heater to full cold, looking up under the steering column at the air mix motor and then turning the heater to full hot and seeing if it actuates the air mix flapper.


This is the actuator linkage you're looking to watch. That picture is taken basically from the driver's side door.

(Image thanks to Twofer, I think)

Do a search for "air mix" in title only and you should get better troubleshooting advice than I give.

 

What the heck is a logicon??? LoL

 

Where exactly are the "hoses going into the heater core"?

When I turn the key to ON and move the **** from cold to hot / vice versa I hear the door moving. So I'm thinking it must be the heater core.

Cheers,
iSP33D-for-J3SUS