I recently installed a new multifunction switch to fix my continuously moving wipers. Today when I went to realign the blades, I noticed it spins backwards. So basically, it would start in the up position, down, then back up (or down smashing into the hood) I checked the linkages and it makes no difference what angle the lever is mounted at, it always spins backwards. Any ideas?

 

2 wires crossed/wrongly placed in the MFS (multi function switch) would be my guess. It's the only thing you've changed & now you're having issues.
Could be the wiper relay (under the hood I think people said it was located) but you only changed the MFS, so I'd look that over 1st.

 

I agree with rotti

I wonder what was the power issue you had . You have not responded to your old thread.
https://blazerforum.com/forum/genera...s-74528/page2/

 

All the wires seem to be in check.

And about that one, one of my tools slipped and messed up a wire on the ignition switch. A little splicing and she was all good.

 

Update: Apparently I was sold a switch for a 4 door, so I returned it and got one meant for a 2 door. Got it installed, same problem! Except this switch cost an extra $200. Any ideas?

 

200$ holy hell man go to a bone yard!

 

Bone yards aren't an option when they don't have the proper vehicle in stock.

 

The pulse module on the wiper motor is known to have problems with cold and or broken solder joints. Hate to say it, but that might be the whole problem. Dorman OE Solutions 906-136 - Wiper Pulse Board | O'Reilly Auto Parts

 

I forgot to mention I replaced this part a few months ago when my wipers were moving non-stop ( https://blazerforum.com/forum/lighti...hut-off-71857/ ) which turned out to not be the problem, so I put the original back in. They only started going backwards (but quit the non-stop) after I put the switch in, unless the new switch and the old pulse board aren't compatible or something?

 

Bought a new pulse board and same problem. Wipers still go backwards.