I replaced the camshaft but now my van won't start it is a 1997 chrysler town and country

If you are using after market parts your problem my be that the parts are defective. The cam sensor uses a magnet to generate a signal. To put it simply the magnet moves through a coil generating an electrical impulse. If the magnet is weak the signal is not strong enough to be recognized by the car and it simply cranks. I used a simple method to test the viability of a replacement part. I took the bolt that holds the sensor and placed it on the flat area of the sensor and slowly rotated it in my hand keeping the sensor level. If the bolt fell off the sensor it is not strong enough to provide a strong enough signal to the car. I went to four different parts stores and tested their replacement sensors; all failed the simple test. I ordered a MOPAR part (I HATED DOING THIS) and it passed my test and the car started immediately. BTW 1997 Chrysler T&C Lxi