Post 4.44 swap starting issues

[EndeavorSVX]

I just finished the installation of a 4.44 in my svx. I'm at the point where I'm filling all of the fluids, but I need to get it started to circulate the atf and coolant through the system. When I go to turn the key, I get nothing. Not even a click from the starter.

The handbrake and abs light are the only lights on the dash that come on. If I push the manual button, the power and manual lights come on, but dimly.

I have the relay mod installed. I'll be trying to start it again later today with a jump start.

Could the interlock switch on the passenger side of the transmission be dead? I got the 4.44 from a junkyard and I don't know how long it sat there.