97 Screen Washers not working

Been a while since I last posted so be gentle with me.

Got a 97 K2500 4x4, the front screen washers have stopped working and the intermittent wiper system also seems to be erratic.

I have swapped out the pulse module for another one, this was after doing the re-soldering job on the first unit as suggested on line, this didn't work so replaced from a known good unit.
The wipers work correctly on slow and fast speeds.
The mist function starts the wipers for one sweep but no washer fluid or pump noise.
When I switch on to intermittent wipe, the wipers do one sweep but then nothing until I move the intermittent to something a bit less delayed then again one sweep of the wipers followed by nothing.
I have checked the washer pump and it works fine when connected to a battery directly.
I used a multi meter to see if there was any power on the red wire that goes to the pump when the washer button is pressed but there is nothing.
When I put the multi meter across both wires of the pump connector I get a reading of 0 volts, press the washer button and the wipers sweep the screen and the volts reading goes to between 10.5 to around 11.6, however when the washer button is in the off position the volts are still reading around the 11.6v and only starts to drop down very slowly after about a minute, eventually after a long while the reading will fall back to 0 volts.
Now I have no idea what to test or where. Is there a relay somewhere just for the front washers?
Anything else I can test or look at? All help gratefully accepted.

There is no relay.

There is the "wiper" fuse, the "multifunction" switch, the wiper motor module and the washer pump motor. And 2 grounds.

The wiper motor module controls everything from inputs from the wiper/washer (multifunction) switch.

Make sure all the contacts are clean inside the wiper motor housing.

Hi, Thanks for the quick reply. I'm getting down to the point that it is probably the multifunction switch itself, one last stab would be the two grounds as the vehicle has been laid up for a couple of years.
Could you point me towards where the two grounds are located for the wiper circuit as I have a fair few grounds in the engine bay, would be easier to know exactly where they are and I can then make sure they are clean and making contact correctly before I go getting a new switch.
Temporarily I have swapped over the rear and front washer hoses so I can get fluid on the screen by pressing the rear screen washer but this then brings on the rear wiper as well but does get me out of trouble at the moment.

Ok, I found one of the earth's, the tab inside the wiper motor, checked for continuity from the earth terminal inside the wiper plug and get continuity from there to the pulse board, the body of the wiper motor and the wiper motor body to the body of the vehicle.
Still no washers for the front screen and everything else the same as before.

I've looked on evilbay for a multifunction switch and they are not that expensive so might just go and get one to try it out rather than mess around much more, aparently a couple of weeks for delivery. Will post back results as and when.

Well the multifunction switch arrived safe and sound and is now fitted, however, the switch has made no difference whatsoever to the front washers not working or the intermittent wiper delay issues, it is exactly the same as before I fitted it, any ideas what to check or test?

Well just had another thought, would anyone know what the colour of the 5 wires that go to the wiper motor are and in what order. When I pull the connector out of the motor and I am looking at the open ended terminals I have Brown Wire to the top left with a Purple Wire top Right. Then there is a Black Wire in the central single connector and on the bottom end I have a Yellow Wire to the Left hand side and the final Right hand side Wire is Red.
Hope that makes some sense, it's just to confirm that the wires are indeed in the right places as I'm running out of ideas.

Many of us have a lot of money invested in factory manuals, all of which are copyrighted. We can give some insight based on what the trouble shooting in the manuals say. Beyond that ???

My suggestion is to get a subscription to http://alldatadiy.com/buy/. $30 for a year and you get all the factory manuals for a fraction of what we paid for our hard copies.

Good luck to you.

When I bought my truck 8 years ago I also bought a CD with the manual on it but after a move and other issues I can't locate the damn thing.
Not an issue, I have jury rigged the washers for the front so I can get the truck through our yearly road worthiness test, I was just trying to get it to work as it should.
Thanks anyway for your input.

According to my diagram, A is red(should be battery voltage when the washer switch is pushed), B is blk(is ground which you know is good because you have lo/hi wipers), C is yellow(hot in acc or run), D is ppl(full bat voltage when sw in hi pos), and E is brown(voltage will vary depending on position of switch, but goes to full battery when washer switch is activated)....all these test are done with the harness connector on the motor and the lines are back probed with a test light to ground....

A quick test........disconnect the harness from motor....use a jumper wire from D to A....with key in run position, washer should run when you rotate sw to hi position....

With sw in off position,and key in run, jumper C to A, pump should run.....

With sw in off pos, and key in run, jumper E to A......pump should not run until the washer sw is depressed.....

This tests all the leads from the wiper switch to the wiper motor.....if the washer works in all the tests, it is a bad cover module or not the correct one for this wiper motor....

Thanks for taking the time to reply, I will be home in the next hour or so and test everything as you suggest and let you know the results.

Managed to test everything with the following results.
With the connector still on the wiper motor:
A) the red wire has no power at all
B) the yellow wire only has power in the run position not in the acc position.
C) the black wire is fine as the wiper does work in low and hi speed.
D) the purple wire has power in the hi position.
E) the brown wire has full voltage when the washer switch is pressed and various readings when the wipers are running.

The test with the connector removed and using jumper leads the washer motor worked exactly as you predicted.

So by that logic then I need a new board for the wiper motor?

Thanks very much for your help, much appreciated.

Just a quick up date as I hate it when you follow a thread and you don't see the answer or the thread just stops.
I went to my local american parts store this morning as they had the pulse board in stock. Fitted it all up and the exact same symptoms have happened, so I then fitted a complete known wiper motor and board (this is the board I swapped in once before to check) and the exact same symptoms again.
I can only conclude that my particular issue is not a standard one as I never get power on the red/pink wire so assume it must be something else in the wiring system and I really don't have the time or inclination to go look for it anymore.
As I said I have jury rigged it so I can get through my yearly test so in real terms it's not a major issue now, just a bit annoying as it should work as per the factory fitment and I've spent money on trying to get it to work correctly, heyho never mind.
Once again thanks for your help.

If not the board, there is a bad connection in there somewhere.....