Wiper Switch

[67Boomer]

Hello:

The windshield wipers on my 67 do not work. Can anyone here help me by providing a logical way to diagnose the problem? For example, is there some way to test the switch first, then move on to the wiper motor itself?

Thanks in advance for your help,
Phil

 

[bobmanx]

67Boomer, according to the shop manual it says, to check the dash swich do the following:
With ignition switch turned on check for 12 Volts at center (No. 2) terminal of wiper unit terminal board. Check also for 12 Volts at the Brown lead terminal which connects to washer pump.

DASH SWITCH:
1. check dash switch mounting. Loose mounting can cause intermittent operation.

2. To determine if dash switch or wiper is defective try operating wipers independantly of dash switch as follows:
Connect 12 volts supply to center (No.2 BROWN wire) terminal of wiper terminal board and connect a jumper from terminal (No. 1 YELLOW or RED wire) to ground. wiper should operate in "Hi" speed. To check "Lo" speed operation connect an additional jumper wire from terminal (No. 3 RED or YELLOW wire) to ground.

I would also check the fuse with a meter to make sure that it is not "Blown" and check the ground strap for the wiper motor to make sure that you have a good ground connection. Everything else that it says to check requires that the wiper motor be on the bench ("park or Latch mechanism")

Good luck and I hope its a simple fix.

Bob

 

[WayneC]

I don't have a 67, but assuming the 63 wipers are the same:

1. check the fuse for the wiper circuit

On the wiper motor there is a 3-wire connector for the motor itself and a two-wire connector for the washers

2. remove the 3-wire connector from the motor, leaving 3 male prongs exposed. The prong that held the center wire (brown) should have 12v to it when the ignition is on. Likewise, the brown wire connector at the pump should have 12v.

3. Apply 12v to the center prong (should probably have had a brown wire on the connector). Now use a jumper to ground each of the other 2 prongs, doing first the top prong (yellow wire), then add a ground jumper to the bottom prong (red wire). The first ground jumper should operate the wipers at full speed, the second will cause it to slow to half speed.

4. check the connections at the back of the switch; I think these simply complete the ground circuit, so the harness could be tested with ground jumpers at this end, also.

 

[Subfixer]

Both replies above are correct. The switch completes the circuit to Ground as stated above. When in the "slow" position, it grounds both outer terminals of the motor connection and in "hi" it only grounds terminal 1. There is a constant 12V to the center terminal (terminal 2) of the motor connection when the ignition is on. Remember not to confuse the 2 wire connection to the washer solenoid with the 3 wire connection to the wiper motor. The 3 wire connection is under the motor/housing.

 

[JohnZ]

The grounding of the wiper switch to the cluster is a key issue - GM wiper systems work by supplying full-time power to the wiper motor (the brown wire) and controlling the motor speeds by grounding control circuits AT THE WIPER SWITCH. If the wiper switch is loose in the cluster or making poor contact with the cluster, you'll have wiper/washer problems. The cluster ground itself is also essential (single black wire from the harness that plugs onto a spade above the tach on the back side of the cluster "can"); if that's loose or disconnected, any grounds are purely accidental, and the wipers, lighter, and all the miscellaneous light bulbs in the cluster will be intermittent or inoperative.

 

[67Boomer]

Thanks to all of you who posted...I appreciate all of your help! I've printed out the responses and will start to troubleshoot my wiper problem shortly.
Thanks again,
Phil (67Boomer)

 

[carrollm]

Turn your wipers ON and touch a ground wire from a wiper case screw to the engine block. They should start working if there is a ground problem. Also double check your fuses.
Make sure you have good wipers on it (if it has not worked for a while), so it dosen't ruin your winshield.

Hope this helps!

64 Mike

 

[67Boomer]

Thanks for the tip 64 Mike. This should be a quick and easy check for a grounding problem.

Phil