wipers

hello im new to this forum and have a wierd problem
my father owns a 1986 dodge ram 250 van 318 motor rear wheel drive.
the problem has to do with the delay in the wiper system.
when the engine is off, the delay works fine, but when the engine is running, the wipers have no delay and just stay at one speed.
all of this with the switch in delay mode.
we have replaced the motor, switch, and relay
any ideas will be awesome
thank you
steven

anybody?

forget it ill asked the 16 year old down the street
im out