I hope this doesn't appear twice; my first submission seems to have disappeared. Sorry...

While driving home today across Penna., my wipers suddenly began to operate -- both front and rear. The only way to turn them off was to turn off the headlights. Here are the symptoms:

Headlights on -- wipers run
Headlights full off -- wipers stop
Parking lights on -- no wiper action
Headlights on, then off to parking lights -- wipers continue to operate.

A ground problem back-feeding current to the wipers? Perhaps the electrical switch portion of the ignition switch assembly?

Thanks in advance for your assistance!

Rob Kuhlman

I agree that it's probably related to the wiper switch/stalk. I would remove the top and bottom covers of the steering column (screws above and below, either phillips or Torx) and inspect the wiper switch where it mounts on the column.
There's a slight possibility that wiring in the back is feeding power back into the switch too- especially if you know that other things don't work back there. The wiring harnesses to the hatch contain a lot of different circuits, including parking lights, constant power to park the rear wiper, power locks, etc etc. Some could get crossed if the harnesses are toast going through the hinges. They usually have damage if they haven't been replaced.
If you want to isolate this possibility, open the hatch. Pull down the very back edge of the headliner from it's retaining groove across the top. There's a round plastic connector up in each corner containing 5 or 6 wires per side. Unplug them and see if the front wipers behave now.

Good luck!
--
Rob Bareiss, New London CT ::: '87 244DL/M47- 234K, '82 245T/M46-182K, '89 244DL/AW70- 212K Not too distant past: 86 244DL 215K, 87 244DL 239K, 88 744GLE 233K, 88 244GL 147K, 91 244 183K

I'll take a look at the wiper switch assembly tomorrow after work when I can pull the two plastic covers off.

I'm not inclined to think the tailgate harness is involved -- I rebuilt both harnesses last summer as 'bypass' harnesses, and there's no strain on those wires any more. But if I come up empty on the switch, then I'll check out the rear end.

Rob

Try wriggling the wiper switch around.

Almost sounds like you're driving the old 89 blue wagon I sold for scrap...&^)