04-05-2014, 09:17 AM
this one will be interesting to troubleshoot. i am not close to my coach right now, but i seen to remember there is a temp sensor at the bottom of the radiator on the side near the rear of the coach. i dont remember if it is for the ddec, the fan or maybe both. does anyone know if the ddec puts out that signal to turn it on or not?
i think if i remember right that the relay turns it on for low, but rather it turns it on high when the call for extra cooling comes from some sensor. the way i tested to see if the high speed comes on the fan is to just disconnect the relay when it is running and on low. so i am not sure if that relay has anything to do with the low speed turn on.
i suspect there is 12v to turn the fan on when the engine is on. then the relay kicks it up to high when it gets on mine a little over 200 degrees. that takes it quickly down to below 200.
so i hope this sparks some thoughts on the issue and where that 12v to turn the fan on comes from and if i am all wet or not.
come on brainy ones, lets help him
tom
i think if i remember right that the relay turns it on for low, but rather it turns it on high when the call for extra cooling comes from some sensor. the way i tested to see if the high speed comes on the fan is to just disconnect the relay when it is running and on low. so i am not sure if that relay has anything to do with the low speed turn on.
i suspect there is 12v to turn the fan on when the engine is on. then the relay kicks it up to high when it gets on mine a little over 200 degrees. that takes it quickly down to below 200.
so i hope this sparks some thoughts on the issue and where that 12v to turn the fan on comes from and if i am all wet or not.
come on brainy ones, lets help him
tom
2014 Haulmark 40' Super C on Freightliner Cascadia ISX15 Easton 13 speed
Former Owner 1990 38' Newell Coach 236 8V92
Former Owner 1999 45'8" Newell Coach 526 Series 60
Former Owner 2002 45'8" Newell Coach 608 Series 60