Thread: what causes cooling fan relay failure
View Single Post
  #13 (permalink)  
Old 07-10-2021, 04:24 AM
gcarm gcarm is offline
CC Member
Visit my Photo Gallery

 
Join Date: Feb 2015
Location: Sydney, NSW
Cobra Make, Engine: G-Force with LS1
Posts: 54
Not Ranked     
Default Cooling Fan Failure
You may need to place a snubber across your relay contacts.

A fan is an inductive load. When you switch off the fan relay, the electromagnetic field in the fan collapses, and as a result a very high voltage is generated across the relay contacts. This causes an arc, and eventually the relay contacts deteriorate due to this constant arcing at fan switch off.

A snubber ( series resistor + capacitor) should be placed across the relay contacts to prevent this arcing. Search online for a suitable snubber circuit for a 12v fan.
Reply With Quote