Is there any easy way to wire my Englander fan to my furnace fan?

[Badfish740]

I'd really like to have my furnace fan come on (I can turn it on from the thermostat independent of the oil burner) whenever my Englander fan comes on just because it could use the extra airflow to get the warm air circulating. My thermostat has 4 wires-is there an easy way to determine which ones control the fan and to connect them to the Englander blower switch?

 

[Duetech]

I have a separte T stat for my boiler air X in my oil furnace and it runs a separate relay to run the blower independent of the oil furnace controls.The fruncae place I bought the relay from told me how/where to connect the leads to prevent a voltage "feedback" through the relay. Maybe you could find a shop close to you who wants to sell a relay.?. Mine was about $85. They may worry about liability and want to do it themeselves but that's not a bad idea either.
I had an englander connected to my furnace and it just dumped hot air into the plenum and would sometimes trip the furnce blower. If you wanted a primitive type simple thing to try then you could try dropping the furnace blower "on" limit switch. (that way the furnce blower would come on at a lower temperature though). My current set up runs the blower with either or both of the blower relays separately or together.