Wipers will not shut off. New wiper motor/board and new Multi switch

[97 heavychevy]

Greetings 97 heavychevy,

The '97 FSM has a pretty detailed section on diagnosing incorrect windshield wiper operation. I've
extracted a few bits & pieces to further the troubleshooting. Given your comments above, my gut
feeling is that somehow an excessive current draw from the washer pump motor toasted something
in the pulse/timing control circuitry? (Based upon the history of the original washer motor blowing fuses?)




My first question became how long do we have to wait before the motor will park/shut off after pressing
the wash button?

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So the 6-seconds of running after the washer button is released also comes from the
'pulse circuitry' board, instead of receiving an outboard status signal.

So the FSM has a selection of different diagnostic trouble flows based upon unique symptoms.
Here's the list:

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And here's Procedure #8:

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Alright. Given that you have already replaced the switch, you could assume that the left side
of the flow has already been accomplished. But at this point I'd still be willing to try the
jumper setup (as detailed in the input conditions) and see if I could get the wipers to Park.

And if the motor still runs? Well, when they say 'replace motor', it's actually the motor assembly,
including the 'pulse circuitry'. In the interest of science, the FSM does give the procedure for
swapping out the circuit board...so if you end up here, why not remove the circuit board and see if you
can locate any visual clues of what got taken out?

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Who knows? Sometimes you find a toasted trace,
and a short length of 14 gauge copper wire can be
soldered in to save the day. No doubt there's others
in here who reflowed solder connections and fixed
blown traces.

If you have any extra wiper motor assemblies lying around,
possibly mix & match sub-assemblies until you get a winner?

At the very least, if you replace this assembly outright,
be sure to take the wounded motor assembly apart & take
some clear photos of what you discover before you put it
back together and turn it in as a core? (If required?)

All of the above is just a thumbnail sketch. But a more
complete answer can be found in the '97 FSM.

Hope this gave you some additional troubleshooting ideas.

Best of luck --

This is what I was needing, thank you! I suspect washer motor is shorted and possibly fried that portion of circuit on new wiper motor/board. I'll do some testing tomorrow and give an update.

 

[sneakingfart]

The wiper controls are on the left stalk.

The actual switch--and the wires attached to it--are in the column.

$140 for a turn-signal lever seems unreasonably expensive.

Mine cost me about $250 for my '99 Suburban. You can buy Chinese knockoffs for under $50, but considering how much of a pain in the ass it is to do this job, I only wanted to do it once.

 

[97 heavychevy]

So did run that test Road Trip posted and jumped the terminals, motor did not move at all, but may be already in park. I took this as it is resulting in needing new switch. Checked back over wiring under hood as I already checked in dash, found wires pinched under hydro booster I replaced over ten years ago (I was in early 20's possibly a teenager, cut me some slack lmao) Red and brown wires smashed, red wire possibly shorted. This is probably a root cause, repaired wires, tried wipers, same fricken thing. I'll re-run that test with jumping wires tomorrow.

 

[RQL557]

As title says, if ignition is on, wipers are moving. Same speed on all settings until moved to high, will speed up accordingly. Replaced motor/circuit board do to it randomly stopping, everything worked great until I tried to use washer on switch (had blown fuses in past when using so was curious) Have since tried unplugging wiper motor, washer pump, unhooking battery, hook everything up, does the same thing. Thought maybe bad Mult switch, $140 later and a bunch of cussing, same result. Thinking new motor has lost park signal or it's supposed to get a signal after using washer of when to stop. Any input is appreciated, thanks. Edit 97 Chevy C3500

Mine was the circuit board inside the motor. Just remove the outside panel and it’s sitting right there. Easy fix. GM guy said you don’t need to change the motor.

 

[Caman96]

Replaced motor/circuit board

Mine was the circuit board inside the motor. Just remove the outside panel and it’s sitting right there.

OP replaced circuit board per first post.

 

[Road Trip]

So did run that test Road Trip posted and jumped the terminals, motor did not move at all, but may be already in park. I took this as it is resulting in needing new switch. Checked back over wiring under hood as I already checked in dash, found wires pinched under hydro booster I replaced over ten years ago (I was in early 20's possibly a teenager, cut me some slack lmao) Red and brown wires smashed, red wire possibly shorted. This is probably a root cause, repaired wires, tried wipers, same fricken thing. I'll re-run that test with jumping wires tomorrow.

@97 heavychevy,

Congrats on finding the root cause of the short 'only when the wiper washer motor is commanded to run'. Check out the wiper switch/motor/washer
wiring diagram. I colored the wires to match the coding to make it a bit easier to follow. And looking at your picture the color of the wiring involved
in your discovery *does* match the following diagram:

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The RED wire is hot only when it is supposed to drive the windshield washer pump motor.
This is the one that you reported the damaged insulation when it was pinched. Your analysis
is supported by the wiring diagram in the FSM. Your finding and fixing this should prevent
another iteration of the short on the red wire from taking out whatever got toasted on the 'Solid State Logic'
module.


Now to figure out where that short you discovered goofed the board that's in the exploded diagram seen in
the last image on reply #8.

Good find on the long ago wiring harness pinch. Looking forward to your next update.

Best of luck!

 

[edon]

As title says, if ignition is on, wipers are moving. Same speed on all settings until moved to high, will speed up accordingly. Replaced motor/circuit board do to it randomly stopping, everything worked great until I tried to use washer on switch (had blown fuses in past when using so was curious) Have since tried unplugging wiper motor, washer pump, unhooking battery, hook everything up, does the same thing. Thought maybe bad Mult switch, $140 later and a bunch of cussing, same result. Thinking new motor has lost park signal or it's supposed to get a signal after using washer of when to stop. Any input is appreciated, thanks. Edit 97 Chevy C3500

I had the wiper staying on issue with my '97. Long story short, turned out to be the old, hardened grease on the motor "contact wheel". The hard grease was lifting the circuit board "fingers" and not making the park contact. Cleaning off the hard grease and relubing solved my problem. I don't think it is the OP's issue as a new motor shouldn't have that problem, but might help someone else with intermittent issues.

 

[97 heavychevy]

Finally got some free time today, performed that procedure 8 test, left wipers in upright position before test. Looked back over that procedure, noticed I missed the ground I was supposed to run to center pin in picture first time running test. Ran test, wipers kept going nonstop pointing to needing to replace wiper motor. Removed circuit board and looks like a circuit has burnt towards bottom of board. Getting it warrantied and new part will be in tomorrow, will likely swap boards because replacing the whole thing was a PITA! lol.

 

[97 heavychevy]

Delayed update, but its fixed! Swapped circuit boards after repairing wires and everything works as it should. Hopefully this post will provide others with another place to check when dealing with similar issues. Thanks everyone for the help!