Intermittent Wipers not Working

I recently bought a '99 Tacoma Prerunner w/ 100K miles for my son and the truck runs great. The only problem I have is that the intermittent wipers do not work, wipers work fine on slow and fast, but not all on intermittent. Any ideas why?

Thanks, Jon

 

Jon- Sounds like the problem lies not in the wiper motor, but in the controller. I recently bought on ebay an intermittent wiper stalk(the control mechanism). Nothing wrong with the original, but I always wanted intermittent wipers. Got instruction on replacement of the control arm, and found it to be very simple. So my point being to get a replacement controller, which ever one would suit you. All discussion sites seem to have great info on replacement procedures.