Uhm, wait a minute, I was talking about feeding 24v to the plugs through a switching current regulator, that would limit the amount of current they can drain, to obtain the same wattage=heat produced as when they are fed with 12v. I'm pretty sure that if you feed the plugs straight on 24v you will burn them, no matter if they are Indusa or Delco, as from what it has been said here in previous posts all of them are really rated at 12v only, not 24v!
Please correct me if I missed something, but from your post CCATLETT I understand you were to use resistors only to cheat the voltage sensor of the original GP Controller/relay.