This remarkable DIY was written by newcomer rolsen11 on how to fix broken headlight wipers if one just stops working out of the blue. This is the repair process he did on his 2000 V70 to fix the solid state fuse that sits between 2 copper strips. The following is his writeup taken from his post in the 850, S70, V70, C70, V70-XC 1992-2000 forum.
rolsen11 »
Late last year I disassembled and repaired the drivers side headlight wiper actuator in my 2000 V70. I took some photos of the process but haven’t posted them anywhere until now. There are tutorials online about how to get the actuators out of the car.
The component that fails is the solid state fuse that sits between 2 copper strips. The fuse tends to corrode or otherwise just go bad.
The hard part when it comes to disassembling the actuator is getting the plastic cover off. I used several razor blades to push the tabs down and dig into the plastic to keep the tabs held down (it should go without saying, but if you also decide to use razor blades be very careful to not hurt yourself).
Once you have the cover off, you will see a gear with an arm, the motor, and the fuse next to the motor.
The only thing we need to worry about for this repair is pulling out the old fuse and soldering the new one to each strip. The metal plate assembly that contains that plastic gear with the arm can be removed for easier access. Be careful not to change the position of the gears as this can affect the parking function of the actuator.
BE CAREFUL with the position of this specific gear. It is what tells the actuator when to park. If it gets pulled out of position you will have to finick with it for a while until it’s in the right spot. You can test the function of the actuator by plugging it into the vehicle harness and operating the windshield washer switch before putting the actuator into the car.
Try your best to get the copper strips moved out of the housing for more clearance. The new fuse can be found from Digi-Key with the part number RGEF400 made by Littelfuse. It’s coated and has 2 solder leads rather than being an uncoated square like the old one. Solder each leg to each strip like shown.
MAKE SURE THE COPPER STRIPS DO NOT TOUCH EACH OTHER AFTER SOLDERING. This would bypass the fuse and the motor can burn up if the wiper arm ever gets stuck.
I didn’t get a picture of it, but I used 2 pieces of plastic and liquid rubber to insulate the otherwise exposed solder and leads from ever touching each other.
It also wouldn’t hurt to put new grease in the actuator as the old grease is over 20 years old now.
