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Discussion Starter #1 (Edited)
I've searched the forums about this topic, but wanted to start a new thread to try to consolidate all the info. I was having trouble with no heat from my vent fans and replaced the thermostat (it ended up being just a disconnected actuator rod from the temp control knob). Anywho, i made the mistake of getting a thermostat from Autozone, and I believe the one they gave me was a 92d. The more I've been reading the posts, I've realized this is probably bad. So, I'm in the process of performing a complete cooling system overhaul (new rad, hoses, thermoswitch, t-stat, probably water pump) which the car is in desperate need of anyway.

However, in the meantime, I wanted to try to hook up my AC fan to allow for some manual additional cooling. The A/C in my Saab hasn't worked for years. The switch in the instrument panel works fine, i checked that, but when i press the snowflake nothing happens. No AC fan on, no clicking of the compressor, no RPM drop. I don't care about the AC, but was hoping to be able to use the snowflake switch to just turn on my fan when I need it. Right now, my regular fan doesn't kick in till the temp gauge is at 2/3 to 3/4 (due to 92d t-stat), which makes me nervous about the head gasket.

Any tips on doing the manual switch, as well as general advice for replacing radiator/water pump/ etc. would be greatly appreciated.

Sorry for the length.
 

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There may be something wrong with your switch. On my 91S the normal operation of the fans is as follows.


If I unplug the red wire going into the top of the AC compressor body then when I push the snow flake the driver side fan turns on.

This is exactly what you are trying to do, but something might be wrong with your AC system that prevents this normal operation.

I would find out what is wrong with your AC and fix it, then unplug the compressor clutch power and use your fan just like I do.


If your system pressure is too low for the ac to work you should be able to take the wires off the pressure sensor at the reciver/dryer and short them out to bypass. this is ONLY if you are going to disable the compressor, otherwise you'll destroy it.
 

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I had to put a manual switch on mine as well....and I like it better, keeps the engine temp in the range that I want while in traffic.

I ran a line straight from the battery to a switch I mounted in a blank plate on my dash...I don't have heated seats...don't need them in Florida. I then took a line from the switch to the radiator fan. I unplugged it from the harness and ran 1 line to the switch and grounded the other to the frame.

Been working like a champ for over a year for me. You just need to hit the switch when in stop and go traffic and turn it off when cruising.

It may not be an ideal way to fix it, but it is a great, inexpensive fix.
 

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Discussion Starter #4
s900snt said:
If your system pressure is too low for the ac to work you should be able to take the wires off the pressure sensor at the reciver/dryer and short them out to bypass. this is ONLY if you are going to disable the compressor, otherwise you'll destroy it.

That seems like the approach i have to take. The AC hasn't been run in literally 4 years, so i'm sure there's no pressure (or not enough). When you say "disable," do you mean just removing the red wire? or is it something more?

Thanks for the response!
 

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disconnecting the red wire will disable the compressor clutch and effectively disable the entire compressor. yes.

If I knew I wasn't going to use it for a long time, I would take the belt off too.
Not for any real reason...just because.

The compressor is the only thing run from that belt, so it just makes sense to me.
 

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what color is your car? inside? automatic, manual? miles?


Just curious, I feel a bond with the other B212s on the board.:cheesy:
 

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Discussion Starter #7
s900snt - thanks for the posts. I found the pressure sensor, unplugged the red wire from the compressor, shorted the sensor wires together with a crimp connector, and VOILA! Now I have a back-up cooling fan. Clever trick, thanks for the tips!
 

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my fan doesn't come on at all. does anyone know of a wiring diagram so i can just bypass the whole temperature sensor or whatever and just hook up a toggle switch to it? thanks...
 

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First check if the wiring from the sensor is ok by connecting them together. The fan should come on. if it does Just connect 2 wires parallel to the existing ones on the sensor or leave the sensor out of the electrical circuit alltogether. Lead the new wires , you connected to the wires of the sensor, back to the dashboard and put in an extra switch. And presto.

btw. When i renewed my radiator and put in an 82 degrees saab thermostat. The overall temp dropped considerably (!). Something to think about if you have an old radiator
 

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therealturbofan said:
my fan doesn't come on at all. does anyone know of a wiring diagram so i can just bypass the whole temperature sensor or whatever and just hook up a toggle switch to it? thanks...
Fan:

Here's a wiring diagram, but I think that it's for an '87. Your will be different, but prolly not by much. If you have a Bentley (you do, don't you?) it should be in there.

http://saabpics.org:3000/gallery/album217/AC_with_time_delay_relay

(BTW, this is for the rad fan activated by the A/C.)
 

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no, i don't have a bentley... otherwise i prolly wouldn't be asking.

is the sensor located about halfway up the radiator on the driver side?

and what do you mean the radiator fan activated by the A/C? i have no idea what you're talking about...
 

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There should be two radiator fans in your car. One fan (I believe the one on the passenger side) is controlled by the thermostat. The other fan runs for additional radiator cooling only when the air conditioner is on (that's the one that this thread is talking about).

The main cooling fan info is here:
http://saabpics.org:3000/gallery/album215

All of the info should be there...
 
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