Eurovan A/C

I have a 2000 Eurovan that the dealer said needs an AC compressor. I replaced the compressor and had the system refilled with oil and refrigerant. Now the system builds huge pressure(300+) and when the compressor kicks on the motor dies becasue it can't turn the compressor. If the solenoid in the rear of the van was bad could it cause this? If not what would? The system was flushed when the new compresor was replaced.

300+ psi!!!! either they filled the compressor with WAY too much oil or the h-block it pretty clogged... The h-block somewhat equalizes the pressures on the high and low side. If its stuck closed it will give high pressures depending what side its stuck closed. What "solenoid" are you talking about?