turn my AC on and the air never got cold

[rjterry32]

99 GS Eclipse AC Problems
The other day I went to turn my AC on and the air never got cold. Went to put a can of freon in and it wouldn't accept it. I then noticed the AC Clutch wasn't kicking on. I then checked the fuse box and the 10A fuse was blown. Replaced the fuse and TADA, blows fuse immediately. Same 10A AC fuse. Tried another fuse and does same thing. Sounds like I have a short somewhere in the circuit. I have no clue on where to start. Does someone out there have a Good (ie not haynes) wiring diagram. I'm really lost on what is wrong here!WTF

 

[poonman]

here you go bro, strait from my alldata

 

[luv2rallye]

This may be the one he wants (from 99 factory manual).

 

[rjterry32]

Ok guys. I just had a serious round 1 on troubleshooting. I need somebody's help that has some electrical know how. My father has a fluke meter and I used it today and here is the results that I got. ANY help is greatly appreciated.
B - Black (on plug)
YG - Yellow Green (on plug)
YR - Yellow Red (on plug)
PT - Positive Terminal (Battery)
NT - Negative Terminal (Battery)
Fuse - you guessed it
G - Ground (know ground on car)
+ - Positive wire on meter
- - Negative wire on meter

Ω Meter - Connector on compressor is plugged into compressor
Fuse(+) Fuse(-) No Ω
Fuse(+) G(-) No Ω
G(+) Fuse(-) Ω Reading
Fuse(+) NT(-) No Ω
Fuse(+) PT(-) Ω Reading
PT(+) Fuse(-) Ω Reading
NT(+) Fuse(-) Ω Reading

Ω Meter - Connector on compressor unplugged
Fuse(+) Fuse(-) No Ω
Fuse(+) G(-) No Ω
YG(+) G(-) No Ω
YR(+) G(-) Ω Reading
B(+) NT(-) Ω Reading
NT(+) B(-) No Ω
Fuse(+) NT(-) No Ω
Fuse(+) PT(-) Ω Reading

V Meter - Connector on compressor is plugged into compressor
Fuse(+) Fuse(-) 0V
Fuse(+) G(-) 12.6V
Fuse(+) NT(-) 12.6V
Fuse(+) PT(-) 0V
PT(+) Fuse(-) 0V
NT(+) Fuse(-) -12.6V
G(+) Fuse(-) -12.6V

V Meter - Connector on compressor unplugged
YG,YR,B(+) G(-) 0V @ each individual colored wire
G(+) YG,YR,B(-) 0V @ each individual colored wire
YG,YR,B(+) PT(-) -12.6V
YG,YR,B(+) NT(-) 0V @ each individual colored wire
PT(+) YG,YR,B(-) 12.6V
NT(+) YG,YR,B(-) 0V @ each individual colored wire
Fuse(+) G(-) 12.6V
G(-) Fuse(+) -12.6V
Fuse(+) PT(-) 0V
PT(+) Fuse(-) 0V
Fuse(+) NT(-) 12.6V
NT(+) Fuse(-) -12.6V

When I have the A/C button pushed in and the ignition on, the 10A fuse blows for the A/C.
I done all this troubleshooting with the key off I don't think it really makes a difference though.
I have some car troubleshooting background and from what I can see, I think that the compressor(that has the clutch on it) is shorted or grounded out inside of it but i'm not realy for sure.
If anyone out there can help it would be greatly appreciated b/c i'm supposed to go on vacation to the beach on friday and the drive will suck really big ones w/out any A/C.
Thanks!

 

[schoffs4]

un plug the ac comp.. an try a new fuse and turn it on that will tell you if the short is in the comp. or the wiring

 

[poonman]

Thats not always true my friend. There could be a short before the relay or even in the low pressure sensor causing a relay malfunction. Best to always test the resistance first all the way down the line.

 

[luv2rallye]

I'm sorry I mistakenly gave you the diagrams for the turbo. Below are the ones for the NT.
You can see from them that the 10A A/C fuse supplies the A/C compressor clutch relay which supplies the compressor and the compressor ECM. So the short must be in one of those 3 items or in the wiring between them. I'm sorry to say it but all your troubleshooting measurements didn't prove anything. Use one of the following.

One method is to first unplug all 3 items to see if the fuse still blows when you turn it on (if so, the short is in the wiring between the fuse and the relay). If ok, then start plugging in items one at a time starting with the relay to see when the fuse blows (remember if it blows when you plug in the relay, the short could be either in the relay or in the wiring after it). You can also replace the fuse with a 12V bulb to save fuses as described here: http://www.dsmtuners.com/forums/showthread.php?p=1496998#post1496998.

I suggest however to use this easier method which saves fuses. Remove the fuse and connect the ohmmeter from the load side (not +12V side) of the fuse holder to ground. You should read 0 ohms if there's a short. Then start unplugging first the compressor to see if short disappears, then the compressor ECM, and finally the relay. When the short disappears the item you just unplugged (or the wiring after it) has the short. If you still read 0 ohms with all these unplugged, the short is in the wiring between the fuse and the relay.

Let us know how it turnsout. Good Luck

 

[rjterry32]

Appreciate it fellas, heres what i've figured out so far.
When I unplug the compressor, the fuse doesn't blow when I press the AC button.
Does that sound like the compressor is the problem?

 

[poonman]

could be, or the automatic compressor ECM

 

[Defiant]

It's the AC ECU. Mounted on the evaporator.

 

[JPJ2007]

Gah, My 95 gsx is doing the same thing.

Hope you find the problem

 

[rjterry32]

Update-
Well, so far I still haven't figured out the problem. I'm waiting on my compressor to come in. I ordered one from a place called 250auto. They gave me a used one with a year warranty and guaranteed to work upon arrival for only $100.
I see that everybody keeps mentioning the ECM, where is that located on a '99 GS and how would I check it. I have a friend that has a '99 GS Rally Edition, same tranny. If I needed to, I guess I could just swap him out for a sec to check.

 

[luv2rallye]

On the 99 NT the compressor ECM is the box under the blower (turbo has it on the evaporator). You cannot test it - only swap with a known good one. Chances are that it is either that or the compressor clutch (compressor). So unplug them one at a time and check resistance as I described in post 7.

 

[RedTurboEclipse]

Hey guys, I have the same problem on a friends car. Except on turbo model. 95 Talon TSi. Just refilled the AC. Light goes on, fans go on. Doesn't sound like the compressor kicks in. Fuse is fine.

My friend took it to the AC shop to refill. They are saying for an extra $129 they can find out the problem. Of course another charge to fix it.

Everything looks normal to me, but the A/C is not something I'm familiar with. Perhaps its the compressor? Is there a harness or something that connects to it to start it. Don't know where to start. Except the above that I already checked.

 

[luv2rallye]

This may help: http://www.dsmtuners.com/forums/showthread.php?t=254447

 

[ekizenbe]

hey guys, the ac solenoid clicks over but the ac compressor itself isnt getting any power, any ideas???

 

[90gst_sean]

Not wanting to sound like a smart ass, but I'd just pull the AC out. It just gets in the way if you ask me. Once you do a engine swap you be happy not to deal with that 20 pound compressor and bracket on the back side of the engine block.

 

[ekizenbe]

that would be fine except im swapped and ready for some creature comforts.....]]

i tried fuses relays wires, the ac control unit under the dash, the enitre ac box under the hood on the drivers side on the firewall.
i get nothing not even the ac fan turns on.i can get the fan to turn on by jumping some pins on one of the relays under the hood but i cant get the ac to click over, i wired the ac compressor to the battery and it works fine that way. i also checked all the wires for conductivity from their point of termination to the ecu, all was well. any ideas????

help im pulling my hair out!

 

[S_Ranger]

How did you wire the compressor straight to the battery?

 

[luv2rallye]

The compressor (magnetic clutch) requires all the following to be working: dual pressure switch (proper freon pressure), magnetic clutch relay, engine coolant temp switch, MCU, 10A and 40A fuses.

 

[ekizenbe]

i ran a piece of wire from the battery to the compressor clutch wire and the compressor kicked on and boom i have ac. So i know that the clutch works fine. I just dont get it. The ecu is definetly commanding the ac to come on but its not sending any power to the wire that goes to the ac compressor.

 

[Defiant]

It's not the main ECU- the AC has its own. You've bypassed it by wiring directly to the compressor.

 

[rjterry32]

SOLUTION FOUND

Alright guys. I got my other compressor in and was looking at how much time this was going to take. I noticed that the high pressure lines was going into what seemed to be another compressor just w/o a clutch on it. There was one line coming out of the front of it, I believe it was a yellow/green wire or yellow/red. Anyhow, that was my problem. The wire was loose from the part and I just had to pull it off and crimp it so it would slide onto the part tighter.

So, this might help anyone that has this sort of problem, even you JPJ2007.

Thanks for the help everyone!