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)
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?)
Thinking new motor has lost park signal or it's supposed to get a signal after using washer of when to stop.
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 --
