Curious issue with wipers / AC

[Clafoun]

Not sure if this is the right thread for this.. but doing a search didn’t bring any related posts up..

I have a strange gremlin that relates to my windshield wipers.. any time I slide my AC to the off position while my 85 GMC is running the wipers cycle once and then park themselves.

Does anyone have any thoughts on what could be causing this?

 

[Jwernatl]

that's truly wacked. is there a mushroom that could be the gremlin?

 

[bedwards]

I have the same gremlin, but mine does it sometimes when I start the truck. Haven't figured it out yet.

 

[R Carnella]

It's probably a bad wiper delay module.
Mine had a very similar problem whereas my wipers would cycle on intermittently.
I replaced the wiprer delay module that's under the Steering column and never had the problem again. I found an ac Delco one on rock auto