my 99 jimmy's rear wiper has started acting up. a couple instances the switch did nothing for about the time it takes me to get to and from work, and the next day its back to normal. no noise, no movement.

as of right now sometimes i get a buzzing sound when i switch the power on to low/high and it goes away when i turn it back off. sometimes it buzzes when its off and goes away when i switch it to low. it seems there is no pattern, it just doesnt work right and makes noise. every now and then i will just be driving and all the sudden i hear a clicking from the back of the truck (the window motor is all thats back there really). the wiper seems to be slowing down lately and not as strong? i was able to assist the wiper by hand when it was buzzing and it would wipe again, then when i turn it off instead of going off it just falls and starts buzzing.

i was assuming that because of this behavior the motor had power but was probably faulty. I went to a wrecking yard and pulled a motor out of a 1995 blazer which mounts and plugs in identically to mine, however the problem has had no change. makes the same noise and will let me assist it by hand etc.

is it possible a fuse could be bad or is that not possible since it is getting power. and what else could i check? is it just possible that i bought a bad motor from the wrecking yard due to bad luck ? a new aftermarket one is 75$ and a new one from GM is 165$, the wrecking yard only cost me 15 bucks, i can return it and try another one when i find one, but just looking for advice on my next step to solve this problem

thanks
justin

 

Given the schematic (attached), the problem almost has to be in the switch in the dash.

 

ok i will take the switch out and look inside it. I have soldered in a white led for the bulb in there to make the icons light up blue instead of teal, maybe there is a problem going on inside there. ill let you know what i find. thanks for the suggestion

 

alright, so i have taken my switch out and looked at it, and i cant see anything that looks bad. I am not ruling out the switch yet. I bought a reman wiper motor from autozone for 70$. It didnt come with the black plastic box attached to it that the motor plug attaches to, so i swapped mine off of my old unit. I installed it and i have the same problem. Ive now tried a complete motor, and the module attached to it from a wrecking yard, my original motor and module thing, as well as a reman motor with my module. if this was your vehicle where would you go now? i am willing to order a switch off of ebay or somewhere, but right now i dont want to dump hundreds of dollars into a stupid wiper =/

right now if i put the wiper on high or low and i go back there and lift the wiper off of the window it moves fine, but it doesnt have enough strength to move when i let it sit on the window.

http://youtu.be/Y9Tu5slxJO8

sorry for the music in the background, my neighbors like to blast their stereo

 

this video is of the motor without the wiper on it VIDEO0023 - YouTube

 

Did you figure out what is wrong? I had the same problem, but now the motor doesn't work at all. I wonder if there is a short preventing full voltage to the motor. In my case it may have shorted out completely now.