Anyone have the 'real' AC circuit diagram for '84 944?

Ehab · 05-04-2002, 07:21 PM

Hey guys, I've been blowing my fuse #6 whenever I turn the AC switch on ... so I thought it was the AC clutch. However, now whenever I put a new fuse in (25amp), and without turning the AC on, the fuse blows whenever the fans kick in as the coolant temp hits 1/2 ... I really need to figure this out before I go through the hassle of the AC clutch ... in case there is a simpler problem that needs to be fixed first ...

The Haynes circuit has been proven wrong before, especially when it came to the cooling fans, so I would really appreciate it if anyone got their hands on the 'correct' circuit diagram.

The one on the Paragon website is incomplete (not scanned in completely, so it is missing some details that are really important)

Thank you ...

E

Ehab · 05-04-2002, 07:38 PM

Upon looking at the relays that are relevant to the AC system, I found that there are 2 ... the AC system relay, and the AC Fan relay. The fan relay is a simple relay that costs 7bux from Pelican, and I think that is relay #3 on the relay board ... if that is the case, where the hell is the AC system relay located? which is supposed to be a double pole relay with 6 pins, not 4 ...

please help.

Thanks.

Ehab

drew1 · 05-05-2002, 03:56 AM

Ehab,

I'll try to luck through some stuff today & see what I have elec dia.

I'm thinking, it might be something in the fans. Short the temp switch on radiator to cut one on & see if fuse blows. If not this one must be OK. Unplug the other fan & cut AC on. If fuse blows it seems like it is in wiring or relays you were talking about.

drew1

Ehab · 05-05-2002, 11:23 AM

Thanks Drew, I would really appreciate it ...

I tried disconnecting the fans today, one at a time, but the fuse blew regardless, whenever the thermoswitch was on. So basically, the fuse blows if the thermoswitch turns on, or if the AC switch is turned on ... which makes me wonder if this problem has anything to do with the AC clutch ... I starting to doubt that.

E

Ehab · 05-05-2002, 11:24 AM

Wilk ...

These are the same jpg images on the Paragon website, which are missing essetial pieces that connect the two pages together, so they are kinda useless ...

Thanks though,

E

Moneyguy1 · 05-05-2002, 05:35 PM

If the fans will run when directly attached to the 12 volt source, then the fans are OK. If you keep blowing the fuse with the fans unplugged, then it sounds like there is a direct short somewhere. I had a 924 that did this. Unfortunately, I had to design an additional relay circuit to operate the fans, "apeing" the original but with the relay located under the hood. The power leads to the fan were frayed and would short against the stub frame.

Of course that car (fondly remembered) had other electrical problems as well. That's when I learned that NOTHING on a so-called generic wiring diagram could be trusted. What they call "engineering design changes".......Oh well....

Break the circuit down into it's smallest components..

Try the fans directly to battery and ground

If OK, then

power source to fuse

fuse to relay

relay to fan

(this assumes that the circuit that operated the relay is operating and you can hear the "clack" when actuated.

I hope this helps. Just take it one step at a time.

Bob S.

Ehab · 05-05-2002, 08:36 PM

Bob S,
The fans work fine, it is the AC fuse that blows ... which is what I'm trying to debug.

Thanks though

E

Moneyguy1 · 05-05-2002, 09:35 PM

Do you have an ammeter you can put in series with the A/C lutch windings?

Ehab · 05-06-2002, 06:59 AM

I do, but it tops out at 20amps, so if the 25amp fuse is blowing in the car, then the ammeter fuse will blow as well before I make a measurement.

E

Moneyguy1 · 05-06-2002, 08:06 AM

You may have shorted windings in the clutch. Not uncommon.

Bob S.

drew1 · 05-11-2002, 11:56 PM

ehab,

location of relay for AC & location of relay for blower shut off - below glove box of trim panel behind knee guard.

it seems like there is a relay to the right after you take the glove box out, too according my memory.

fuse 6 on addition fuse panel- wt/bk wire feeds ter 30 AC relay contact ter 87

from ter 87 bl/re to evapator van (fan?)
bk to vac valve solenoid coil
bk/yel to amplifier
bl/yel to fresh air blower interlock relay coil(may be blower shut off relay)

sorry late with info, hope its accurate & helps.

drew1

clinton · 11-07-2003, 10:45 PM

let me know what you find out about your problem i have the same thing going on