North American Turbocoupe Organization



A/C Fan controller
B_Lieder Offline
Senior Member
#1
For the past 2 years i have owned my 88 t-bird the aux fan hasn;t come on when the air is on. I have been putting it off and now its time to fix it.

The main fan works like it should no problems. i have relayed them both together so they both come on at the same time. I jumped the connector to the A/C pressure switch and the aux fan came on. I probed the tan/orange wire on the IRCM and got 12v. I haven;t cut the t/o wire to see if the main fan would come on, but it works because i have them wired in sequence.

My question is: How can the A/C pressure switch be replaced. It is directly on an A/C line. Will i have to bleed out my freon to replace it. The car does blow cold air so it still has freon. I am assuming the a/c pressure switch is bad only because the aux fan came on when i jumped the connector. Is there anything else i should check? I would like to get this fixed before it gets horribly hot outside. I have thought about getting an adjustable controlller for them, but i would to think of that as a plan "b"

Any Help Appreciated....
Thanks


------------------
Bill Lieder
1988 TC stock until summer
Bill L
Reply

Pete D Offline
Administrator
#2
The secondary (driver's side)fan only comes on in A/C mode when A/C head pressure exceeds something like 310 psi. I don't much about A/C but others have said it has to be pretty hot outside for that to happen. I guess what I'm saying is, given the above are you sure it's not working properly?
Pete Dunham


Reply

B_Lieder Offline
Senior Member
#3
Yep, I bought the car in Alabama....So, it get hotter than Hell down there in August. I have never seen it work. I had the car down there durning the whole summer of 2001 then moved up here to Ohio. I relayed them both together after i moved up here. So in short, it hasn;t worked on its own. Oh yeah, the aux fan motor was replaced after i bought the car....was siezed up.

**I forgot to mention, the aux fan doesn;t come on during KOEO tests. The main fan either but i don;t off hand know if the main is supposed to come on during the tests. Just a little more for the electronic gods***
------------------
Bill Lieder
1988 TC stock until summer

[This message has been edited by B_Lieder (edited 04-18-2003).]
Bill L
Reply

Pete D Offline
Administrator
#4
Bill, have you done the fan test that's in the FAQs?

------------------
NATO Member. it's not a vice, it's an obsession
Good judgement comes from bad experience, and a lot of that comes from bad judgment.
88 TC X 2, 86 SVO, mods list at
http://www.turbotbird.com/showroom/pd_88tc.htm
Pete Dunham


Reply

B_Lieder Offline
Senior Member
#5
Pete,
I have tried the fan test except for the pink wire thing. I will do that tomorrow. You called the secondary fan the driverside one, i thought it was the passenger-side was the aux fan. According to my EVTM it shows the pass fan as the aux and the driver side one as the main. I am i looking at the picture wrong?? The fan or fans do not come on during the self tests. I have never heard the fan come on when the car first starts up either. But, when i warm the car up on a cold january morning, come back outside to get in, i do then hear the fan come on for a few seconds then shut off.

------------------
Bill Lieder
1988 TC stock until summer
Bill L
Reply

Pete D Offline
Administrator
#6
Bill, Not sure what your seeing in the EVTM.
Give me some page #s.

My point of refernece is Vol D Powertrain, Section 27-10-1 Fan, Electro drive Cooling.

Four Blade(Passenger Side) Fan: (paraphrased)
This is the one that turns on at the lower temperature (200*F) and runs whenever the A/C clutch is energised. (It's also the one that is suppose to run for a few seconds each time the engine is started.

Seven-Blade (Driver's Side) Fan (paraphrased)
This one comes on when temps reach 220*F AND the 4 blade fan has run for at least 10 seconds.

Also comes on when A/C head pressure reaches 310 psi.

This section of the manual does not use the terms primary or secondary in the verbal description. Page 27-10-5 has a schematic that does label the ssecondary and I know the EVTM has diagrams that use the terms primary and secondary.

Since the passenger side fan is the first to operate and operates under the most conditions, I consider that primary.

I agree that the fan placement in schematic diagrams is inconsistent with the verbal description and the passenger vs driver's side orientation and it may lead to some confusion.



[This message has been edited by Pete D (edited 04-18-2003).]
Pete Dunham


Reply

B_Lieder Offline
Senior Member
#7
Page 54 of the EVTM. I got the EVTM from Helm inc.

------------------
Bill Lieder
1988 TC stock until summer
Bill L
Reply

Pete D Offline
Administrator
#8
OK, you got me. But I don't understand the logic of the labeling given how they actually work
Pete Dunham


Reply

B_Lieder Offline
Senior Member
#9
Damn hy head hurts. You think maybe i'm low on freon?? I believe (correct me) that low freon won;t pressurize to full potential therefore not causing the A/C pressure switch to kick the fan on??

Just a thought...at this moment maybe not a real good one.

------------------
Bill Lieder
1988 TC stock until summer
Bill L
Reply

Pete D Offline
Administrator
#10
I'm not sure how it works. I know when the freon is somewhat low the A/C clutch & fan cycle on and off sort of rapidly. I'm not sure what happens when it's empty.

------------------
NATO Member. it's not a vice, it's an obsession
Good judgement comes from bad experience, and a lot of that comes from bad judgment.
88 TC X 2, 86 SVO, mods list at
http://www.turbotbird.com/showroom/pd_88tc.htm
Pete Dunham


Reply





Users browsing this thread:
1 Guest(s)



Theme © iAndrew 2018 - Software MyBB