71 Wiper help

[Billy S.]

I'm a newcomer here and I'd appreciate some expert help.

I am trying to fix the windshield wipers on my 71 small block coupe (w/ air).

Problem:
When I switch the wiper switch to low or high the wiper door raises, the relay clicks, but the wipers don't start moving. I know the whole system used to work because on Oct 17th the car went through flight judging and all of the functions worked then.

What I know:
The wiper motor is good. I know this because I sent it out to be rebuilt and it was returned to me as functioning by Steve Hackel. I re-installed the motor and had it running, but had to swap out a sticky reproduction wiper switch with another reproduction switch and since then it won't work.

I have tested the new wiper switch following the instructions in the wilcox video, the new switch shows continuity in all of the same configurations as the video. I have also tested that there is continuity between the wiper switch housing and the metal air ducts inside of the dash.

I have also done my best to confirm that with the car running and the wiper switch in the off position that there is 12v of resistance on the yellow middle wire in the three prong connector. My ground (2 black wires) are also attached securely to the via a connector and bracket and screw to the wiper motor housing.

I have also turned the knob under the steering column to both positions to make sure that the power isn't cut. I am 90% sure that the knob needs to be turned counterclockwise to allow power through.

I personally think the issue is somewhere with the grounding, but I am acting on instinct alone, if someone could tell me how to eliminate grounding as a source of the error I would appreciate it. I am also open to any other ideas or opinions.

[Russ S.]

Re: 71 Wiper help

I hate electrical . Have you checked the fuse?

[Joe R.]

Re: 71 Wiper help

The wiper motor is good. I know this because I sent it out to be rebuilt and it was returned to me as functioning by Steve Hackel. I re-installed the motor and had it running, but had to swap out a sticky reproduction wiper switch with another reproduction switch and since then it won't work.

I have also done my best to confirm that with the car running and the wiper switch in the off position that there is 12v of resistance on the yellow middle wire in the three prong connector. My ground (2 black wires) are also attached securely to the via a connector and bracket and screw to the wiper motor housing.

I personally think the issue is somewhere with the grounding, but I am acting on instinct alone, if someone could tell me how to eliminate grounding as a source of the error I would appreciate it. I am also open to any other ideas or opinions.

Hi William,

The smoking gun seems to be that it worked before you swapped the switch. Can you swap back to the sticky repo switch that works? Did you accidentally disturb any wiring when you changed out the switch? Are all the connections tight?

12 V of resistance does not make sense. I think you mean that you have 12 Vdc where you should, right?

You can check your grounds with an Ohmmeter (Digital Multi-Meter). Check the resistance from a suspect ground to a known good ground. It should be much less than an Ohm (subtract out meter lead resistance). Or you can try temporarily jumpering a suspect ground to a known good ground.

Good luck and may the force be with you!!!
Joe

[Alan S.]

[Billy S.]

Re: 71 Wiper help

Humm I could have sworn my user manual said the opposite... (I don't have it handy at the moment to check) I have been doing the majority of my testing with the knob turned counter-clockwise (towards the drivers side door) so I guess I can retry making sure to turn the knob towards the passenger door.

The smoking gun seems to be that it worked before you swapped the switch. Can you swap back to the sticky repo switch that works? Did you accidentally disturb any wiring when you changed out the switch? Are all the connections tight?

12 V of resistance does not make sense. I think you mean that you have 12 Vdc where you should, right?

I can't test with the sticky switch -- I had to send it back.

Yes I mean to say when I put my meter into DC testing it registers around ~12 when I have one lead on the engine and the other on the middle prong of the three way connector

[Mark E.]

Re: 71 Wiper help

Hi William,

The smoking gun seems to be that it worked before you swapped the switch.Joe

I'm with Joe. While troubleshooting, it's always good to ask, "What's changed?" If it worked before swapping the switch, then focus on the switch and whatever may have been disturbed.

[Billy S.]

Re: 71 Wiper help

I tend to agree with the what's changed sentiment -- what else is back there behind the wiper switch bezel that I could have messed up or missed?

All I see are the three wires which connect to the wiper switch via a three way connector. I've made sure to reconnect them well -- with the tab pointing towards the passenger seat and I have also confirmed my ground wire from the wiper switch to the dash vents is providing continuity (I will remove the wire and install the wiper switch bezel once I get the wipers working this way I don't have to take the wiper bezel in and out constantly).

[Jeffrey S.]

Re: 71 Wiper help

Years ago on my '69, the wipers worked with a door or hood open but not when all was closed. Turned out that the ground at the starter was bad and the wiper motor was grounding through the alarm system. Check the ground at the starter (I assume that your '71 wiring is similar to the '69). Just something else to check.
Jeff

[Alan S.]

Re: 71 Wiper help

Hi William,
The 71 owners manual DOES say clockwise to STOP the wiper motor, but the trouble shooting info I have states counter-clockwise.
I'd check on my car but the wiper bay is apart.
I just took a look at the switch, and it's turned clockwise; I'm thinking the wipers were NOT stopped on the windshield the last time I tested them and shut the ignition off. So I'm still thinking 'counter' to STOP them.
I may have you worrying too much about this switch and not what the other reasons for your problem might be. Can you temporarily bypass the switch to see if that makes a difference in the operation of the wiper motor and then move on to other trouble shooting?
Regards,
Alan

[Billy S.]

Re: 71 Wiper help

Another clue: I tested for continuity between the grounding spade screwed into the wiper motor and the ignition shielding on the driver-side and I did not get a solid beep, it was either non existent or fuzzy and only rarely a solid beep depending on how things were jiggled. There are two black wires which lead into that spade, one I can track to the hood alarm pin switch, the other disappears into the wiring harness somewhere. Where does the black wire which disappears into the wiring harness ultimately get its ground source from? Maybe my problem is there? I am thinking that the poor/intermittent ground might explain why it worked before and doesn't work now.

[Billy S.]

Re: 71 Wiper help

Hi William,
The 71 owners manual DOES say clockwise to STOP the wiper motor, but the trouble shooting info I have states counter-clockwise.
I'd check on my car but the wiper bay is apart.
I just took a look at the switch, and it's turned clockwise; I'm thinking the wipers were NOT stopped on the windshield the last time I tested them and shut the ignition off. So I'm still thinking 'counter' to STOP them.
I may have you worrying too much about this switch and not what the other reasons for your problem might be. Can you temporarily bypass the switch to see if that makes a difference in the operation of the wiper motor and then move on to other trouble shooting?
Regards,
Alan

I am 99% sure its clockwise to get power. With the knob turned towards the passenger seat there is power on the second wire in the three wire connector, and none when counterclockwise.

[Alan S.]

Re: 71 Wiper help

Hi william,
You're right!
I was able to test the wipers on my car and while sitting in the seat turning the knob to the right (clockwise) sends power to the wiper motor.
The ground wire that Jeff mentioned which exits the harness near the starter must be in place for the motor to run. It's typically on one of the starter mounting bolts.
Regards,
Alan

This is a 71.

[Billy S.]

Re: 71 Wiper help

Alright -- this weekend I will check/clean the ground on my starter (need to travel for business till then), thanks Alan for the super clear pictures!!

Because I am so new to all of this I want to confirm that I am not making a mistake though: testing for continuity and finding weak/intermittent continuity between the spade you have pictured above and the spark plug ignition shielding (chrome plate, mounted to the engine block covering some of the spark plugs closest to the transmission on the drivers side) is a good way to confirm whether or not I have ground?

[Billy S.]

Re: 71 Wiper help

Okay after much hair pulling and ground checking I have found the problem!

The problem was my wiper door limit switch. Taking the limit switch out of the equation by jumping the connect there made my wipers turn on and run perfectly.

I guess the limit switch (which appears to be original, the wires are soldered onto the switch and wrapped with black heat shrink) must have given up the ghost or must be fritzy and inconsistent.

Also for what its worth my wiper cutoff switch needed to be turned clockwise (towards the passenger seat) for my wipers to work.

Thanks all!!!

Billy

[Mark E.]

Re: 71 Wiper help

Billy,

Good job, and thanks for updating us with the resolution. This one was tricky- the system stopped working after one part was replaced (the wiper switch), but it turned out the failure was due to another part (limit switch). Coincidental and multiple failures are the toughest.