Vari speed wiper switch

He wants a variable speed . Looks like a 3 speed switch but has a rheostat inside. The motor itself is the same for both variable and 3 speed aplications .
I have 2 of those switches but want to get my wipers working before I let go of one .
Do you have one that doesnt work ? They are easy to take apart and clean... just try not to break the groundstrap loose while doing it.