Weak heater, motor is swapped, Logicon being naughty?
 

I have had this problem since I got the car, virtually.

And I am really tired. It is easily down to -10C here, that would be 14F. Driving without any pressure from the heater, with a bit too low water level (so I don't get too much heat into the heater) and a broken side window, it is COLD. Really cold. Probably around 14F.

I am sure I almost died yesterday while driving for 3.5h to get home, and I need to take this more seriously.

So. I have tested the blower with a 12V PSU from a computer, blows a good bit. Tested in car, blows like shit.

The wires are inside the coupe, so I have to take the stand that they are okay, as there is not much moisture that can cause corrosion inside the car.

That leaves my 24 year old Logicon. People say the heater in the RX7 is really good, and could easily make you sweat, even when it is cold outside.

I have yet to see this happen to me, I always wear a winter jacket in my car in the winter, not because it's cold outside, but because it is just as cold inside, or close to.

Now, the problem with the Logicon is, as I understood it, it that it is hard to test. The only thing I can do is have the car running and measure the volts over the blower motor connector and see what I get. This I have not done yet, but I have a feeling it will be pretty low, closer to 11 than 14V.

I have been looking through the wiring diagrams, and I can't see any other links that can go bad between the Logicon and the blower motor except the relay, which is set up in a fashion that I can't just swap it with a regular Wal-mart item (in lack of a proper store name).

Before I freeze to death (6h drive next week), I need help!

you could resolder it(the logicon) and see what you get after that. have fun unplugging it though.

Logicon's just don't hold up to age very well re-soldering tends to help, but you're on a time crunch. The heater system is quite beastly when working.

If you're really in a pinch, bypass the logicon control for the blower.
Hook up the 12v relay to power the fan blower connected to a manual switch. Turn on fan blower as needed.

you should also check that the heater valves motor is working, they frequently don't. it also might not be a bad idea to turn the heat on, turn off the car, unplug the heater hoses and flush out the heater core, since its not on all the time, they can get filled with crud.

the heater should be fine @14c with the top up, it was only like 7c here this morning

I wrote MINUS 14c :P

But yes, I tested the output from the Logicon now, I got 10.5-11V with the engine NOT running, so I would probably end up with a respectable 13.5V to the motor when the engine is running.

However, that means the Logicon is not as bad as I thought, BUT, the blower did still blow better when I connected it to a 12V computer PSU.

As for the blower motor, isn't the same used in loads of cars (literally a 100 cars?), so I could basically pick up a blower from a 99 Corolla and it would work? I think it was something like that.

The blower I have now is from an 89 or 91 Mazda 626 anyways, after the brushes died on the last one.

On a very unrelated note, a BAC from any car should in theory work on any engine, as long as it actually does work? It is just a spring and a diaphragm and something more?

Either my BAC from an S4 N/A doesn't work, or my ECU isn't outputting the correct signal to it.

Just try another one. All the FC BAC's were the same, they just have the metal inlet pipe oriented differently; you can fix that easily.

lmao! i knew it was weird that it was the same temp in California AND Norway!

I am running an S4 N/A now, no difference when my TPS is set to 1k ohm (and that makes the butterfly valves completely shut, I should add). So it might be that there is a wiring or ECU issue somewhere between then. I will get to measure the volts some time, but I can't as my car can't idle, so I can't go out to do it myself.

Yes :P And that makes it straight forward dangerous to drive here without a proper working heater (and a side window, but that is another issue)