Donovan0131 Report post Posted April 8, 2016 Just purchased a 2002 Monaco Diplomat. The fan on the dash unit works only on high no matter whether sent on A/C or heat. or mode. I will be adding R134a as it is low, but I think the fan is a separate issue. Help Share this post Link to post Share on other sites
huffypuff Report post Posted April 8, 2016 If the fan only works on high, it is possible the resistor has popped and needs to be replaced. Share this post Link to post Share on other sites
ClayL Report post Posted April 8, 2016 There will be a resistance wire coil for each speed except high which is direct. Location of the resistor package depends on chassis brand but is often in the heater/AC air plenum. The moving air is used to cool the resistor. Share this post Link to post Share on other sites