You can't run it without a heatsink in something the size of the Dreyfuss, it'll smoke it in no time.
Really, you want the CC-M for this job if you're replacing the DCDS, you're doing it the hard way with the Cruise Commander.
BTW, just because it runs at low speed, that is NOT telling you the magnet and sensor is fine. The spacing and magnetic force is more critical at higher flywheel RPM.
There's two ways to fix these. One is to throw parts at it until it runs, the other is to diagnose the actual failure and replace that part.
I'm still not convinced it isn't the R2LC, did you swap that?
