AC fan problem, not turning on.

[meximan]

Spent last weekend installing AC and all that good stuff..Took it in yesterday to have them EVAC + charge the system.

Picked it up today and it blows cool, but the owner of the shop told me that the AC fans arent turning on so its not blowing COLD...Which is true, when i push the button i dont hear any fans turn on....

So is there something i can check, or something that controls the activation of the AC fan so i can get this baby cold?

[sk8too]

You need to figure out if your fans are working correctly, pull the coolant temp sensor thats on the side of the radiator and jump the wires and find out if your low and high side works.
do this

[meximan]

thanks sk8!

I just did this test...

The low setting works. The high didnt work.

So now what?

[sk8too]

Bad FCM find a good one install should be good to go


Boo ya tapatalk! If you haven't got it yet get it!

[meximan]

Alright.....I know whats been done....Gotta love buying other peoples problems!


Alriight so I wondered when i was re wrapping everything in the bay WTF all these fuses were about....It appears the PO of the car already did some job of a FCM Delete...The low speed fan works as it should, turns on when its hot , stays on after the cars off until its cooled...

However, The highspeed does not work.

Im thinking trying to track down and reverse this mess, and throwing a FSM on it would be a bigger pain in the ass then , Figuring out a way to wire up the high speed.

So going with this route, The factory thermoswitch is still on the car...I did notice there was only one standard bosch relay wrapped up in these inline fuses...Im assuming if the vw fans work anything like the taurus fan im putting in my rx7, to run two fan speeds you need two relays...

Any info on people Running a two relay setup with a working A/C Dash button?

P.S Last pic i checked the Relay #1 to make sure there was a relay for the A/C options and there wasnt so i threw a std, bosch relay in there to see if it did anything.

Heres pics.

[sk8too]

Id try and find the 147 relay for the #1 relay or 13 relay


Boo ya tapatalk! If you haven't got it yet get it!

[meximan]

any of these other open spots important as well?

[StaceyAnthon]

Boo ya tapatalk! If you haven't got it yet get it!
[img]http://www.************/6d.jpg[/img][img]http://www.************/d.jpg[/img]

[meximan]

ttt

[meximan]

ttt

[meximan]

went to two junkyards today looking for a FCM..20 cars later not a single one >.<

[meximan]

I tested some plugs with a test light...

The Large plug that goes to the FCM, only has power at the red/white wire...the red/green wire does not have power (with the ign off)

I checked the Thermo switch plug as well...Low speed lights up, high speed does not.

and with the radiator fan plug off, i tested both sides and both dont light..Im assuming because it needs to be triggered by the thermoswitch..

SO SHOULD the large plug at the FCM have power on both red/white and red/green wires? Is my problem perhaps behind that plug?

[meximan]

[meximan]

I tried tracing the red/green wire through the fire wall, But I couldnt find the other end near the fuse block and im a BIG dude, didnt have a whole lot of wiggle room....Does anyone know where that wire goes to inside the cab? Like does it link to one of the relays on the back of the fuse block?

[sk8too]

Red/grn goes to your FCM, all the wires on the large plug going to the fan motor go to the FCM, they don't go through the firewall. Got any buddies you could ask if you could borrow their FCM for a quick trouble shoot? But like I said if your low speed fans do not kick on when you push the ac button and they work when you jump the plug it's almost a guarantee it's the FCM. And all your fuses are good right?


Boo ya tapatalk! If you haven't got it yet get it!

[meximan]

yeah i changed all the fuses, and the PO of my car deleted the FCM, i dont have one on the car at all , its all hardwired, also missing another peice thats bolted to the strut tower with a plastic cover as well..

So im figuring rather than "trying" to reverse what the PO has done, Figuring out a way to wire up the high speed would be easier.

Im assuming on the large plug that left and right terminals/wires are power for each individual speed, and that top and bottom are the grounds and that through the stock FCM these would be triggered VIA the Thermoswitch...So im guessing the left red/white wire is power for low speed and the right red/green wire are power for the high speed, and both should havea constant 12v power.

IF thats true then im not getting a 12v power to the red/greed plug that supposed to go to the FCM, If im not gettin power at that point, then further down the line at the other two plugs , they arent going to work either right?

[meximan]

ACtually i think i may have just figured it out...AFter tearing apart the harness that i re wrapped...all that Wiring garbage, with fuses ect i took pics of, is from something else, a small loomed wire that goes across the windsheild cowl.

The green/red wire on the FCM plug goes to the Radiator fan, not through the firewall like i assumed.

The red/White wire on the FCM plug has constant power, from i think the battery terminal.

and the FCM relays that red/white to the Green/red when the fans need to turn on. Because i dont have an FCM its not jumping over to the green/red to turn the high fan setting on.

On the coolant thermoswitch theres also a red wire, red/white wire and a ground...the red/white wire goes to the FCM plug, where i think it mates with the red/greens circuit. So when the coolant reaches a certain temp, it pops the thermoswitch over, which activates the red/green High speed circuit....So testing the Thermoswitch plug at this point wont work for the high setting, because The circuit is broken at the missing FCM.

I jumped the red/green wire from the battery, assuming this, and the fans kicked into High gear..

So im thinking with a FCM i might be able to fix that circuit.

[meximan]

sk8 i didnt understand what you meant at first but, now i do

[meximan]

OK Turns out i was wrong,,,

I need some confirmation! First person to help me solve this problem, and get this **** working ill buy a beer!

Does the Green/Red wire from the FCM ONLY link to the GREEN/RED Wire on the Fan motor? Is it ONLY powered by the FCM switching the relay over from the Red/White wire for the Low speed fan?

I have constant power at the red/White Wire, No power at the green/red wire. So im assuming its switched.


I dont fricken get it....I bought the FCM used (but working from a forum member) Is there anyway to test it out of the car?

[meximan]

There is an Orange/ red or pink wire off the AC harness to the FCM, that if grounded will click the relay and get the AC fan setting to work...?

Where does this wire go to from the plug, Im thinking about just running a toggle switch to it and calling it good.