The wipers and heater fan work intermittently

The wipers and heater fan work intermittently. They both mostly either work or not work at the same time, but a few times the heater will work while the wipers do not. No other electric components are affected. When they work, about 20% of the time, they are slower than normal (wipers on high are more like the slow setting, fan only turns slowly). I have replaced the wiper motor and pulse board with no change in function. Truck has a new battery. Now I went to start the truck and it just cranks. I get one code, P1626 the theft deterrent thing. I have checked all fuses, relays, ground connections, etc. Any suggestions? Can I have a bad BCM? Or does that not affect wipers and heaters?