I had that problem on my F150. To make matters worse, intermittent would stop in mid wipe. I would replace the relay and it would be fine for a few months before it was acting up again. I would get relays at the dealer, the auto parts store. It didn't make a difference. Then ten years ago, I popped the cover of the wiper relay with a utility knife blade put a wee bit of light oil on the relay contacts with a small syringe and re assembled. I have never had problems since. I know someone with a Kia Sedona who had the same issue. I gave the relay the same treatment and he hasn't had problems since as well. You are most likely to have problems with intermittent wipers because the computer sends a small pulse of voltage to the relay. If the relay contacts didn't complete the circuit in the span of the pulse, intermittent wipers will not work properly. The relays on both vehicles look like they could interchange with one another.