I hit some spotty rain today. One time I turned the wipers off but they didn’t park - just kept running all the way home. I can tell it’s not the switch, the motor reverses as if to stop, it just keeps running. The power lead goes cold. It isn’t the switch on the dash.
I’m familiar with the wiper motors in the MG and Triumph, I assume the Jag’s are similar. I just don’t want to bugger around if parts aren’t available, I’d sooner send it out.
Anyone find this to be repairable at home, or can I get a recommendation for a reputable shop?
I can’t remember exactly which car you have Mitch so I may be inaccurate.
If you fold the centre dash down there is a square hole in the firewall and behind it is the wiper mechanism. If you look at the picture you’ll see a copper contact held by a screw. This conducts via the red wire to the motor. This is the switch for the park mechanism. Note that Mine is RHD and so parks to the right; the contact is rotated 60 degrees from yours. The contact has a tongue on it which when correctly adjusted parks the motor.
Adjustment is by loosening the little lock screw.
Additionally, some cars have a separate fine tuning mechanism that can make small adjustments to the contact. I have seen these as a little knurled knob on the firewall in the engine bay near the heater valve. Andrew above says they can also be found under the dash although I don’t recall seeing this myself.
My follow up question (similar issue) is where is the likely source for the water leak that I suspect causes this. I’ve been thinking about the rubber gasket under the wiper external bolt?
It’s a weird arrangement. I don’t really completely understand how it works. As Andrew says it makes the motor run in reverse when the dash switch is turned off to a point where it breaks the contact, then it stops. I think…maybe…
Here’s a drawing showing how the wipers in the saloons are wired. The parking switch, drawn “LS PARK”, is internal on the DR3 used in the saloons, and external on the DL3 used in the E. Otherwise, the schematic is the same iirc.
It figures that on a British car, ‘off’ runs the motor in reverse in order to stop. Good Lord they did it simpler and better in the 50’s. At ‘off’, the motor ran til the gearing tripped the park switch. No reverse needed, and to adjust you meerly turned the switch’s case, found on the motor.
Andrew, not jabbing sticks in your cage, but is it correct that the high side of the switch runs through a resistor as shown on your document?
I had a look at the limit switch, it appears to be adjusted properly and a continuity test shows it’s making contact. Shown parked in my photo (LHD).
With the dash switch ‘off’ and the wipers running in reverse, I shook the harness at the wiper motor and it parked. More shaking isn’t starting it up again and it’s working as expected though a few cycles, on/off/park. I’m now wondering how a fault in the harness at the motor would cause this symptom? Is there a connection inside the motor that would cause it to ignore the park switch being open?
No amount of manipulation is re-creating the problem. Any ideas which wire might be at fault? If the wire from the limit switch is open, it would assume it’s in it’s park position and stop at any point in it’s travel. I’m not above suspecting the dash switch, my fiddutzing the wires being a co-incidence.
Funny thing, the WSM shows no fault fix for failure to stop running when switched to ‘off’.
Yea, but when the brass tang is buggered you HAVE to send it out the the guy who has the part. He does do a terrific job though, it comes back running great and properly painted.
