Here's my thought (as clouded as it is by influenza):

My 747 ECM has no fan control. I don't use EGR (Vortec heads and intake don't posses them).

Could I not use the EGR control signal to turn on fans? Set throttle position etc to super low so the 'egr' is on all the time, zero out all the egr influenced corrections of timing fuel etc. Then just use the temperature to control the on point.

Yeah, it'd be crude, but... work with what you've got?

 

This has been talked about in the past, but I don't recall of anyone posting back that they got it to work. Doesn't mean that it didn't work, just that no one claimed to have did it. May be able to find some of the threads on this with a google search of TGO.

If you try it also set the EGR fueling compensation tables to have no affect.

RBob.

 

Ok, so the concept isn't a total delusion induced by fever and Robitusin.

My main concern was overloading the driver transistor. But I guess a relay vs. the EGR solenoid won't be that much different. If I get it to work, or I burn down my ECM I'll post back.