Possessed windshield wipers

Recently replaced fan motor assembly on 2003 Mitsubishi Outlander. Since then, wipers want to spray and wash window without touching control. It kicks on when air conditioner comes on, and headlights also flicker. If we turn off the air con, wipers won’t come on as much. If we turn on the headlights, wipers also don’t come on as much. Without these 2 avertive measures, I have gone through 2 reservoirs of water! Now just run it dry. The shop that did the work says it was simple “plug and play” for fan motor assembly, and now they are “diagnosing” the problem, and charging me 85 buck an hour to find out! I think it is something they did, since it did not do this before.

Ever hear of this? Can someone help?

I suggest you have the ground wires cleaned in the dash area and also the battery to chassis ground. If that doesn’t help then you may need to look at the switch and wiring for the washer circuit and make sure that nothing is bridged to it.