jmamartins

Hi all,

For start, I shall say I am a newby in this posting thing.

I have a stock 1995 3rd Gen Rx-7 which I bought in perfect condition in 1999 with 32.000 kms (about 19.000 miles).

Some time ago the A/C started to act wild. In position #2 and #3 the A/C ligh was On but there was no air getting in from the vents (the fan was off). Now the A/C just works in position #4 (Fan on + A/C Ligt On). In every other position the A/C light is on but the fan is off.

Could this be the fan switch? Any advice for me to check out?

Please help as I love this car and this problem has been on for months.

Thanks to you all and congratulations on your posts.

spurvo

Well, does the fan work at those speeds with the heat on, that is, no A/C?

racerfoo

why is this urgent?

my fans only come on at a certain temp, or with the a/c turned on. do the fan mod if you're really worried about it.

jmamartins

The fan does not work in positions #1, #2 and #3. It only works in position #4.

The A/C light works ok when the fan is in any position. The problem is that the fan is not moving so there is no air coming inside the car.

This may sound like a silly problem but is really anoying

keynote22

Sounds like wiring harness issues. The wiring harness will break down over time causing this exact problem. Its not normally an issue unless an after market ecu has been installed. Installing the new unit will break the wires and or the harness.

here is a thread where they talk about it.

https://www.rx7club.com/forum/showth...r+conditioning

I know a guy in virginia who by-passed the ac controls in the ecu with a switch in his glove box. Good luck

spurvo

No, I think he means the heater blower fan in the interior, the one by the passenger footwell.

martins: the A/C light typically lights up when the A/C button is pressed AND the fan switch is set to 1 or higher. This is fact controls the whole A/C system, as I suspect you already know. I'm pretty sure you have a bad fan switch (again, the one on the interior!). Call Ray Crowe at Malloy Mazda (search for his number on this forum) and he can get you most likely the best price. Then you get the enviable task of pulling that interior piece... yum

spurvo

OK, I think I'm full of **** here. IF your A/C light works at the other positions, BUT the fan doesn't run, THEN the switch itself is likely ok. HOWEVER, I've been pouring over the heater control wiring (section G), and I notice that in the "blower motor resistor assembly" (left middle of the page) there appears to be a fuse between the first three position resistors and the fourth position. It's the little curvey line with a circle at either end in between the lines with zig-zags (which indicate resistors). Anyway, I'm revising my diagnosis to that fuse that lives in the resistor assembly being blown. That resistor assembly is indicated to live on the front of the heater housing, on the furthest passenger side. Check it out...

jmamartins

Thanks man.

You diagnosis might in fact be correct, since when I place the fan switch in position #1 or higher the RPM goes up from 800rpm to 1500rpm and then back again to 800rpm, which indicates that there might be some electrical malfunction.

I will try to locate the resistor based on you tip (front of the heater housing, on the furthest passenger side) and try to give you feedback tomorrow.

jmamartins

Ok guys, got some good news and some bad news...

Good news is that this problem is, after all, diagnosed in page 5-8 of the owners manual. There seems to be an aditional fuse (30A) installed in the blower motor, which is indeed on the passenger's side, behind the glove compartment.

The bad news is that, according to the manual, the stupid fuse is supposed to be located ON TOP of the blower motor. I tryed to locate the fuse but on top of the blower there appears to be only the dust filter (there is a lot of wiring there, but nothing that resembles a 30A fuse...).

Please anyone, send me your schematics (section G only) in order for me to try and locate the wires, as I am affraid if I try it "adventure style" I will get to the end with non intended spare parts and a blower fan that needs relacement...

jmamartins

Sent the car to the dealer and got a new Blower Motor Resistor.

Good news: Finaly... Problem Solved!

Bad News: $120

spurvo

Good for you! Pretty sick how much things like this cost, huh? So at least I was in the right area...

jayk

So is it a Blower Motor Resistor or a Fuse? I have a very similar problem and am hoping to look into it this weekend.

spurvo

I'm pretty sure the fuse is part of the blower motor resistor assembly, and therefore you have to replace the entire resistor assembly. Typical!!