scoooby slayer Posted August 21, 2011 Share Posted August 21, 2011 checked out my aircon and its lost its earth to the compressors clutch relay, if i run a direct earth there it works perfect ! does anybody know where the earth comes from that feeds the relay ? i dont want to just earth it constant im assuming it must come from a sensor somewhere ? any help would be much appreciated its doing my head in lol Quote Link to comment Share on other sites More sharing options...
chrispot Posted August 21, 2011 Share Posted August 21, 2011 if it helps the ac clutch relay is controlled by the engine ecu, a white/green wire according to wiring diagram for the pre facelift manuals. just checked the same on the facelift manual and it is a green/white on wiring block "h" terminal 13. but are you not using a aftermaket ecu? if that is the case then there is a seperate ecu for ac which has other connections to the engine ecu, maybe you could use one of these. i dont think earthing seperately is a good idea as i think it could over pressurize the condenser radiator if left on, hope this helps regards chris. Quote Link to comment Share on other sites More sharing options...
scoooby slayer Posted August 21, 2011 Author Share Posted August 21, 2011 if it helps the ac clutch relay is controlled by the engine ecu, a white/green wire according to wiring diagram for the pre facelift manuals. just checked the same on the facelift manual and it is a green/white on wiring block "h" terminal 13. but are you not using a aftermaket ecu? if that is the case then there is a seperate ecu for ac which has other connections to the engine ecu, maybe you could use one of these. i dont think earthing seperately is a good idea as i think it could over pressurize the condenser radiator if left on, hope this helps regards chris. its on hks fcon vpro 3.2 gold, does the wiring diagram show any sensors between ecu and relay ? or could it be the ecu is not getting a correct reading from any sensor and therefore not earthing the relay ? Quote Link to comment Share on other sites More sharing options...
scoooby slayer Posted August 21, 2011 Author Share Posted August 21, 2011 i have just found how to do a sensor check and rear window demist was blinking on air con check, and i dont understand what the prognosis means ? i did the test by simultaneously turning on the ignition with auto sw and r/f sw switches held down, it did the 4 blink test on all switches then kept flashing number 11 demister indicated switch, it says this in toyota book for the flashing led it has : air outlet damper position sensor value does not change even if a/c amplifier signals the air outlet damper control servo motor to operate ? that makes no sense to me lol, where do i find this sensor that its saying is faulty ? Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted August 21, 2011 Share Posted August 21, 2011 There's a gas pressure switch that ensures the compressor clutch will not engage if the gas charge is below a certain PSI. Quote Link to comment Share on other sites More sharing options...
chrispot Posted August 21, 2011 Share Posted August 21, 2011 (edited) the wiring diagram shows that there is no sensor between ecu and ac clutch relay, if i can find pdf file i will send to you ( i have printed out the manuals) i can do it tommorow, pm me your email and i send when i get in from work, i have not checked fully but looks like the ac amp has the pressure sensors etc then sends signal to engine ecu which controlls the ac clutch relay, i suppose to cut it when engaging at hi engine speed etc. regards chris. or as chris says could be low on gas? have a look in the sight glass on the reciever drier should be only a few bubbles on start up of ac pump. Edited August 21, 2011 by chrispot extra details added (see edit history) Quote Link to comment Share on other sites More sharing options...
scoooby slayer Posted August 22, 2011 Author Share Posted August 22, 2011 There's a gas pressure switch that ensures the compressor clutch will not engage if the gas charge is below a certain PSI. bypassing the pressure switch still doesnt earth the relay mate. Quote Link to comment Share on other sites More sharing options...
scoooby slayer Posted August 22, 2011 Author Share Posted August 22, 2011 the wiring diagram shows that there is no sensor between ecu and ac clutch relay, if i can find pdf file i will send to you ( i have printed out the manuals) i can do it tommorow, pm me your email and i send when i get in from work, i have not checked fully but looks like the ac amp has the pressure sensors etc then sends signal to engine ecu which controlls the ac clutch relay, i suppose to cut it when engaging at hi engine speed etc. regards chris. or as chris says could be low on gas? have a look in the sight glass on the reciever drier should be only a few bubbles on start up of ac pump. my email is billycossie@fsmailnet. wiring diagram would be great mate thank you. i have read some have had issues when running different management as ecu wiring is run to the ecu, might be the problem somewhere ? Quote Link to comment Share on other sites More sharing options...
scoooby slayer Posted August 22, 2011 Author Share Posted August 22, 2011 whos best to use for fixing this ? Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.