# Does the Curtis Controller 1238 need high voltage present to turn on?



## Hugues (Jul 13, 2014)

Caps18 said:


> I looked at the wiring diagram and it makes sense that the KSI needs the high voltage there. I was able to power up the 12V devices in my truck today, but the controller didn't turn on yet. It makes sense now that it didn't turn on though. At least I hope that is the case. I did have one bad vacuum pump switch that caused a smoking and melted ground wire...


That's how my 1238-7601 works yes, needs voltage on KSI to turn on.


----------



## frodus (Apr 12, 2008)

KSI needs to have about 12-24V on it at a minimum to light up the control circuit on the controller. It won't drive, but it will turn on and run a self test.

It's how I program them out-of-vehicle.


----------

