BIG THANKS TO BATUKING for all his help and this nifty pic


some background:
AC system fresly installed vacuumed and filled by shop.
condenser fan tuns on when AC switch is on+interior fan
blows only warm/hot air.
when I jump/power the AC compressor, the system blows cold. (6 deg C / 42 deg F)
ALL fused checked and are running properly

WHAT IS KEEPING MY SYSTEM FROM WORKING PROPERLY????

as seen in this pic, in the upper right there is a box that says "under dash fuse box"

N0. 13 (7.5A)

now on my fusebox it is listed as blank and no fuse goes there? WTF?

anyway i stuck a fuse in there and left it at that. now below that isthe compressor clutch relay and a BLK/YEL wire which should be showing 12V. directly under that is a BLK/RED wire that leads to the ECU.

this wire, when grounded, activates the relay and should turn on the compressor clutch. but it doesnt. i tried just grounding it and the comp clutch DOES engage.

next. the BLU/RED wire to the left of the ECU is the "safety signal" wire that tells the ecu that pressure is ok and temp is ok. what kind of voltage should i be seeing? I believe 12V-14V but i barely see any voltage??!!!

. I have tested the sensors and they are 0 ohms = closed circut = working

can someone see a problem with my theory?? I'm losing my mind.


Modified by Turbo E 604 at 12:45 PM 6/2/2004


Modified by Turbo E 604 at 12:47 PM 6/2/2004

 

Man oh man....i feel your pain as i am in the EXACT same boat as you!! Check your ECU A17, ACC, wire to see if it's giving you a signal. According to the manual, if it's working, with AC off, it should read 12V and 0V with AC on. However, i am always getting 0V yet, the AC compressor is not engaging.

My setup:
- 2000 Si AC kit
- JDM ITR ECU
- 97 JDM GSR engine

EDIT: Sorry, not sure if you are OBD1 or OBD2....A17 is for OBD2. Not sure what wire it is for OBD1.



Modified by Petah at 1:09 PM 6/2/2004

 

I believe my corresponding wires are A5 and A15. I'm a 93 EG SI coupe. P28 ECU

After revieing the diagram and doing some highlighting, I see that logicly for a relay to work it has to have a ground. for the condenser fan it would be the BLU/RED and the Compressor would be BLK/RED. both of which lead to the ECU.

the BLU/RED also lead back to the A/C master switch (dotted box)

when i pulled out the diode (open circut) in the dotted box, the condenser fan stopped. there for the BLU/RED "ground" must have been interrupted/broken.

Hmmm.. I better check the wiring at the ECU I think some things may be switched around from my motor swap...maybe. esp the BLK/RED wire

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Turbo E 604 &raquo;</TD></TR><TR><TD CLASS="quote">I believe my corresponding wires are A5 and A15. I'm a 93 EG SI coupe. P28 ECU

After revieing the diagram and doing some highlighting, I see that logicly for a relay to work it has to have a ground. for the condenser fan it would be the BLU/RED and the Compressor would be BLK/RED. both of which lead to the ECU.

the BLU/RED also lead back to the A/C master switch (dotted box)

when i pulled out the diode (open circut) in the dotted box, the condenser fan stopped. there for the BLU/RED "ground" must have been interrupted/broken.

Hmmm.. I better check the wiring at the ECU I think some things may be switched around from my motor swap...maybe. esp the BLK/RED wire</TD></TR></TABLE>

I worked on the car more tonight....there is no continuity between the ACC wire and prong 3 of the compressor relay. I am thinking it's more my wiring if anything....

 

I had the answer at my fingertips all along.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">when i pulled out the diode (open circut) in the dotted box, the condenser fan stopped. there for the BLU/RED "ground" must have been interrupted/broken.</TD></TR></TABLE>

fixed the problem

when I did my swap to the GSR i moved the AC pin (blu/red) to wire up the knock sensor, as i was using the P72 ECU

now I am using a P28 and there is no KNock sensor pin, so I moved back the pin to the original place and the AC started right up.

I feel so stupid.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Turbo E 604 &raquo;</TD></TR><TR><TD CLASS="quote">I feel so stupid.</TD></TR></TABLE>

Well thats good that it works. congrads.. but we all learn from our mistakes

 

Sorry to bring this back,

But have a problem where the AC will kick on then go off and contiues. If Play around with the harness by the AC system I can see/hear it kick on. Wasn't sure if you were incurring this problem as well.

Thanks.

 

its supposed to turn off and on. when it get sto a certain temp, it stops. when its too warm, its starts again.

it doesnt run non stop,.

 

Yeah I know, but it is not a regular stop start, it kicks in but then will instantly go back off, or will stay on for about 20secs then go off again, but won't come back on.

 

possibly you have low presure in your lines or too much pressure, (unlikely)

get your system tested for leaks and refilled

 

I have had it pressure tested by 2 shops and the pressure is fine. Its going to Honda today.

 

Im having the same issue at the clutch relay I have the 12v on one pin and ground on the other pin and there side I get 12v and the other pin I should get ground when the blower and the ac switch is on but I’m getting 4.9v when on and nothing while off and on my other car when everything is on I get a ground signal