Quote:
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Originally Posted by oab_au
John the Winter/summer switch justs grounds the wire, from the 'wiper control unit' so you can just short the wire to ground to see if it is the switch.
Harvey.  |
Testing the switch in this way is of no use.
It is stated that, “The wipers just don’t park in the higher position.”
The wiring diagram indicates that the wiper motor, as one would expect, incorporates two limit switches. One for the high position and a second for the lower position. It is likely that these switches are in the negative supply circuit. One switch is shown normally closed the other normally open.
With the N/C limit switch is in circuit, the motor will stop/park when that switch opens which indicates this is the high position switch. At this point the N/O switch would close and when this switch is in circuit via the selector switch, this would result in the motor running on and stopping/parking in the second lower position when it opens.
Therefore there are the following possibilities:-
1. The selector switch is not opening the controlling circuit e.g. the contacts are frozen closed.
If this is the fault disconnecting the switch switch should result in the wipers parking in the high position.
N.B. shorting the switch line to ground by way of a test, will therefore not change this possible fault condition. The switch must be tested for continuity, open and closed.
2. The selector switch line is shorted to ground. N.B. If this is the fault, shorting the line to ground by way of a test will prove nothing.
3. The N/C limit switch is opening, but the N/O is not closing, e.g. the contacts are faulty or there is a mechanical problem.
In view of what has been previously reported, it would appear that item three is the most likely cause of the malfunction.
Edit P.S. There is a wiper control unit, but the probable electronic speed control and or intermittent functions are not reported faulty, so that trouble in this respect is highly unlikely.
Personally I do not use the feature proving faulty, as the wiper blades are given a hard ride over the window edge when traveling to the concealed position. Kinder to leave them on the glass.