Wiper problem

[Tbruz]

So my wipers decided to stop working on my 1997 4WD Tahoe; initially would not turn on low or intermittent but would work fine on high and washer worked as well.
Tonight nothing worked so I pulled the wiper pulse motor and noticed that a diode on the pulse board was broken; figured easy fix, under $30.

Bought a Cardone 81-158PB board and installed it; nothing no wipers, no wash.
Not sure if its the replacement board or not.
Suspected the fuse #11, but its good.
Next looked at the stalk itself but everything else works fine, blinkers, high beam and cruise control are working fine.

Pulled my meter out thinking I should see 12v at the 5 wire harness that plugs into wiper motor and am seeing nothing......

I should be seeing 12V at the harness correct??

Any thoughts anyone?
and by the way 5 inches of snow due tomorrow here in the Northeast and this is my DD.....
Tbruz

 

[SunlitComet]

You should see 12 volts going into the motor assemblies yellow wire as well as the yellow wire of the switch when ignition is on. If not turn key on again and turn wiper on high. Do you see 12 volts on purple wire going into the motor assembly?

 

[Tbruz]

Sunlit
Thanks, no 12v on yellow or purple wire, key on wiper switch on high; no joy.
Tbruz

 

[SunlitComet]

Then check for ower on #11 fuse labelled "wipers" with key on. If nothing do radio and power windows still work with key on?

 

[Tbruz]

I have windows and radio, blinkers and cruise control work as well.
I do have 12V with key on (14 volts with engine running) at fuse 11.
Only missing wipers and washer pump

In fact I have these voltages at both sides of fuse 11 with the wiper switch in the off position.
Is that correct or should I only have the 12v on one side with switch off?
Is this pointing to the switch?

thanks
Tbruz

 

[SunlitComet]

with ignition switch is off or lock position you should not see power on either side of fuse. with ignition switch on you should have a hot fuse that then feed the wiper module and switch at the same time.

Again, You should see 12 volts going into the motor assemblies yellow wire as well as the yellow wire of the switch when ignition is on. turn wiper on high. Do you see 12 volts on purple wire going into the motor assembly?

 

[Tbruz]

Sunlit
Thanks for your help and guidance.

With Ignition off I have no voltage on fuse 11, either side

With ignition on I have 12v on both side of fuse 11
With truck running I have 14.x on both sides of fuse 11

Ignition on, wiper switch off, no voltage on yellow wire at wiper motor
Ignition on, wiper switch on high, no voltage on yellow or purple(or any of the five wires for that matter)
Ignition on, truck running, wiper switch on high, no voltage on yellow or purple(or any of the five wires for that matter)
Thanks
Tbruz

 

[SunlitComet]

Then it appears you have a break in the circuit wiring from the fuse to the split where it goes two separate ways. Fortunately for you it happens right on the back of that fuse block. Note your location of the fuse and inspect the back of the block for any damage and probe for voltage downstream of the fuse. I kinda doubt that the wiring going thru the firewall and into the steering column would fail at the same time unless the system sustained major damage. BTW any wash pump action? I suspect that is out to correct?

 

[Tbruz]

Wiper Problem solved............I'm an idiot!

Lesson(s) Learned
First, I need to admit I'm not as good a "wrench" as I think I am.
Second, never trouble shoot in the dark and cold of New England winter.

Facts
Motor pulse board was blown as evidenced by melted/broken diode.
Replacement board didn't work because of a blown wiper fuse

Why didn't I see this fuse as bad?? see line 1 above.

Basically I was reading the rows of fuses wrong and was reading/metering the fuse below the wiper fuse.

Replaced the blown fuse and power to the motor was restored.


So, What caused the pulse motor board diode to blow?
Wiper motor was binding up and the driver side transmission arm was wonky.

New fuse, new wiper motor and new DS transmission and I have the smoothest and most silent wipers since this truck left the factory.

Thanks for listening to my rant
Tbruz, "Wiper Idiot"

 

[SunlitComet]

Cool beans.