Sunday, May 1, 2016

Fixing XJS windshield wipers

Another priority fix - the wind shield wipers are inoperable.
Nothing worked when I started, but they had originally, so might as well start at the end of the chain. Took out the wiper and applied direct voltage to the motor's leads resulting in sparks. Either a hopelessly burnt up motor, or maybe just jammed or frozen.I decided to completely disassemble after reading Ed Sowell's guide.
 
The motor needed the shaft cleaned and lubricated, the the armature and magnets cleaned, the commutator lightly sanded, the brushed lightly sanded, and the... pinion stop?... adjusted. Applied voltage and got two speeds, motor done. The wiper "gearbox" needed all of the old dried grease removed and new grease applied... all two feet of spiral cable, four tubes, and three gearboxes. after that was done it could be spun by hand. Reassemble and test, seemed to work, got different actions with the park switch pressed and not pressed. Tried out on the car and got delay with park and off, but no slow or fast speeds, and the switch caught and dragged sometimes.





So after checking the price of a new switch, complete disassembly of the switch. Drilled out the retaining posts just enough to separate the halves. The copper contact plates had either come loose, fallen out of place, been covered with dried grease, or corroded. Cleaned all, super glued the copper plates back in place, re-greased only what should have grease and reassembled.... with removable pins for the next time!





The result: delay and park, momentary and will park if held, off but no park, Slow but no park, fast but no park. So after running the wipers you can set them to delay or hold momentary momentarily to park. Close enough for this weekend. Reinstall the wipers, and I decided to try the shorten and bend a wiper arm mod. I don’t think shortening was beneficial, in fact it make it hard to avoid hitting the sill chrome on the back sweep, but the bend does make for a neater appearance.