The van usually starts. once in a while the ignition has to be turned on and off several times before the starter will engage. I've talked to other people that have the same problem with the same model year van. is there a relay under the dashboard I should be looking for?

More likely to be a faulty ignition switch.

Remove the Ignition Switch

1. Turn the ignition key to the "On" position and set the steering wheel straight so the front tires point straight ahead. Then turn the ignition switch "Off."
2. Detach the black, negative battery cable using a wrench and wait one minute before beginning to work on the ignition switch.
3. Remove the knee bolster from underneath the steering column. Use a Phillips screwdriver or a ratchet and socket.
4. Unfasten the screws holding the steering column upper and lower covers in place using a Phillips screwdriver. Then remove the covers form the steering column.
5. Insert the key in the ignition lock cylinder and turn the key to the "Run" position.
6. Insert a small Allen wrench into the hole located on top of the ignition lock-cylinder housing. Then push down the wrench to release the lock cylinder from its housing. Then remove the lock cylinder from its housing.
7. Unplug the two electrical connectors that run from the ignition switch-located underneath the lock cylinder housing-to the cylinder housing.
8. Release the ignition switch by inserting tool number J 42759 or similar (see the Resources box bellow for more information) into the two switch access holes. Then remove the ignition switch from its housing.
9. Unplug the electrical connector from the bottom of the ignition switch.

Install the Ignition Switch

1. Insert a standard screwdriver in the ignition lock-cylinder housing and rotate the lock-cylinder housing gear counterclockwise until it hits the stop.
2. View the ignition switch at its mounting position as you face the ignition lock cylinder. Make sure the left tooth, showing on the top gear of the switch, is the flat one. Otherwise, rotate the gear until you set the switch gear in the correct position.
3. Plug the electrical connector to the bottom of the ignition switch.
4. Insert the ignition switch in its housing until the switch tabs snap in place.
5. Insert the standard screwdriver into the lock-cylinder housing. Rotate the lock-cylinder housing gear to the "Start" position and let spring back into the "Run" position.
6. Install the ignition lock cylinder into its housing.
7. Plug the two electrical connectors from the ignition switch into the lock-cylinder housing.
8. Install the lower and upper steering column covers and tighten the screws using the Phillips screwdriver.
9. Install the knee bolster and tighten the screws using the Phillips screwdriver or ratchet and socket.
10. Turn the ignition switch to the "Off" position.
11. Attach the black, negative battery cable using the wrench.
12. Turn the ignition switch to the "On" position and make sure the Air Bag indicator, on the instrument panel, flashes and then turn "Off" the ignition switch.

See if you have power at the purple wire at the "*" terminal of the starter solenoid, with the key in the crank position...if you do and it doesn't crank, check connections at the starter....if ok, need new starter....

If no power, then you have to work your way back from the starter to the ignition switch, checking P/N switch, starter enable relay(if used), etc.