Chrysler Repair: no wiper: 99 minivan, plymouth grand voyager, fuse box

Question
QUESTION: The wiper on my1999 Plymouth Grand Voyager (114000 miles)stopped working. I have checked the fuse, interchanged the relays,installed a new switch and also tried a new motor and none of these worked

ANSWER: There are 2 fuses: fuse 19 in the box under the hood, and a fuse-like device in the fuse box under the dash, #7 slot in the row that is directly under the 4 multi-wire plugs. So check out both of those. Otherwise we will have to do some voltage checks which I can tell you about. Do you have a voltmeter or 12V glow light?
Roland

---------- FOLLOW-UP ----------

QUESTION: Yes, I have a voltmeter. What are voltage checks?

ANSWER: Hi Joe,
Let me first note that simply 'interchanged the relays' may not prove that one of the relays is not the problem, unless you substituted other non-wiper relays with the same part number from the box which are known to be good. Both relays are needed to be good for the system to work properly, so switching those wiper relays from one to the other will not correct a relay problem.

Lets check the motor module first:
Pin 1 should be connected to the middle socket of the hi/lo relay
Pin 2 should be connected to pin 41 of the body control module
Pin 3 should be connected to the rear pin of the hi/lo relay
Pin 4 should be connected to ground
Pin 3 should show 12v when wiper is set to high
Pin 1 should show 12v when the wiper is set to low

At the wiper switch:
Pin 7 should show 12v when the ignition is in the 'run' position
Pin 5 should be connected to the in-board pin of the 'on' relay socket
Pin 6 should be connected to pin 7 of the body control module
Pin 8 should be grounded

Pin 73 of the body control module should be connected to the out-board pin of the 'on' relay socket

When you turn the wiper 'on' you should feel the 'on' relay click.


Check those out and see if you find anything wrong.
Roland

---------- FOLLOW-UP ----------

QUESTION: Pin 3 reading was .02V, Pin 1 reading was .02V and  Pin 7 reading was 12V.  

Answer
Hi Joe,
I now notice that I made one error by reversing those pin 3 and pin 1 voltage readings:
pin 3 should read 12v when wiper set to low, pin 1 should read 12v wben wiper set to high, so please re-check that.
If neither of those two pins at the motor module shows 12v no matter if high or low setting, then the wiper 'on' relay is either not working/has bad internal contacts (did you feel it click?),
 or  pin 73 of the bcm is not connected to the outboard pin of the 'on' relay socket,
or pin 6 of the wiper switch is not connected to pin 7 of the bcm,
or there is an internal problem with the new wiper switch (check that there is a variable voltage on its pin 6 that depends upon what the speed setting is chosen, including 12v when 'off'),
or finally that the bcm is not activating the wiper 'on' relay due to an internal fault.

So please go thru all the possibilities and measure those that can be measured. Let me know what you find.
Roland