bulldogfan Posted July 30, 2020 Share Posted July 30, 2020 Have an 07 mack with the APADS controller. A/c works perfectly, until you come to a stop. Then the problem starts. The engine fan is not coming on. Therefore the high side pressure skyrockets, until the drier pressure relief valve opens. Wow, what a racket that makes! So, I replaced the high side pressure switch and the relay mounted to the apads box. No, difference. So, my question is do these boxes fail? Also, the orange wire coming out of controller is the fan wire. I am not getting any voltage on this wire, even when high side pressure is over 400 psi? What tells the fan to come on? I can get fan to engage if I disconnect the relay, of some of the other connectors nearby. So............... Quote Link to comment Share on other sites More sharing options...
h67st Posted July 31, 2020 Share Posted July 31, 2020 I don't know anything about the APADS, but I figured the compressor would kick off before the pressure got that high. Quote Link to comment Share on other sites More sharing options...
Vladislav Posted July 31, 2020 Share Posted July 31, 2020 Same on APADS experience but could be solved by connecting the high pressure sensor to a separate relay to switch the fan. A kind of a lame customizing but would fix the problem. Quote Никогда не бывает слишком много грузовиков! leversole 11.2012 Link to comment Share on other sites More sharing options...
41chevy Posted August 1, 2020 Share Posted August 1, 2020 (edited) https://www.indexsensors.com/pdfs/apads_faqs.pdf The boxes do fail Section D is fan control info about diagnosing the box Gives diagnostics, blink codes and such. Edited August 1, 2020 by 41chevy Quote "OPERTUNITY IS MISSED BY MOST PEOPLE BECAUSE IT IS DRESSED IN OVERALLS AND LOOKS LIKE WORK" Thomas Edison “Life’s journey is not to arrive at the grave safely, in a well preserved body, but rather to skid in sideways, totally worn out, shouting ‘Holy shit, what a ride!’” P.T.CHESHIRE Link to comment Share on other sites More sharing options...
bulldogfan Posted August 19, 2020 Author Share Posted August 19, 2020 I replaced the APADS unit with a new one. Problem solved. 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.