Wiper fuse keep blowing

[JPPET]

Hi, I have a 97' 4Runner. Some weeks ago we have to remove the wiper motor to clean and grease it(was making a little noise). We removed the conector from the motor, cleaned, greased and reassembled it. The wipers were working fine, without any noise.
After a few days, I went to turn the car on(with wipers off) and the dash lights became very low(like dead battery) for about a second and then come back to normal again(this happened when I turned the key on). After that I have started the truck as normal.
About 3 days ago, when I needed the wipers again(because of rain), I turned the switch and nothing. Went to the fusebox and found the 30amp wiper fuse blown. I changed it for a new one and the wipers worked fine during all the travel.
Today when my dad went to start the car again, the same thing happened(the dash lights became very dim, he tought that was the battery, but the car started normally). When he went to turn the wipers on, nothing. Went to check the fusebox, and another 30amp fuse blown.
Note that the dash lights became dim without the wiper switch on.
What could be the problem?
The wipers are working fine, nothing strange.
Thanks!

 

[JPPET]

Problem solved!
There was a harness at the rear hatch that with vibration and time, began to touch the metal of the hatch and get a little short with the car itself. What we have done, was just separate the harness and isolate it, and now everything is working fine.