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I am restoring a 1978 Corvette. It is an early production (10/77) 78. I cannot find a wiper switch without pulse. My original switch (#470316) is not available. I ordered the only switch available (2nd design) and the wipers run in low speed all the time with key on. My original switch works except for powering up the (new) wiper washer pump. The low/high speed and park functions work fine with the old switch. I followed the Wilcox testing/diag and wiper motor works as designed with the old switch. Anyone ran into this issue or know where I can find the correct switch. The selector shaft is flat on my switch and all the replacement switches have a round shaft. Any advice is appreciated!
At the washer pump you should have a Pink & a White wire.
With ignition switch on you should have power to the White wire at pump.
When you activate washer pump from wiper switch you are sending a ground to the washer pump Pink wire.
Are you getting both at the pump?
May take a second person one at the switch one at the pump...
II followed the Wilcox testing/diag and wiper motor works as designed with the old switch. Anyone ran into this issue or know where I can find the correct switch. The selector shaft is flat on my switch and all the replacement switches have a round shaft. Any advice is appreciated!
I'm going to need this...can you post the link? thanks!
I was looking for this old thread!
OPs Non-Pulse switch shouldn't be that complicated....
To me it sounds like the old switch is switching wiper motor speeds just fine.
As you can see the switch rails can get gummed up or just tarnished overtime.
I suspect just that with OPs switch.
You should find 2 Gray wires at the wiper switch connector.
One will be from the LPS circuit powering the bulb.
All other wires to the switch will be grounds.
Black
Pink
Gray
Purple
Black is the common chassis ground
Gray & Purple are motor speed switching
Pink is the wiper washer pump motor ground
Repairing the switch is probably my best route. Thanks for the reference pics, links and advice. I appreciate yall's information and I will update as soon as I get it fixed. This car is in the last stages of restoration and I'm ready to get it down the road.
The reason the new switch runs at low speed in OFF position is the switch rails circuits are completely different on where the wires land at the main harness connector to the switch.
Is it possible to make a delay wiper switch work without a delay option, sure...
You just need to wire the delay switch when switch is in the off position, #150 and #91 connected.
Low Speed #150 & #91 & #92 connected
High Speed #150 & #92 connected
Washer Pump #150 & #94 connected,,,
Simple
That's how I read it anyways...
The reason the new switch runs at low speed in OFF position is the switch rails circuits are completely different on where the wires land at the main harness connector to the switch.
Is it possible to make a delay wiper switch work without a delay option, sure...
You just need to wire the delay switch when switch is in the off position, #150 and #91 connected.
Low Speed #150 & #91 & #92 connected
High Speed #150 & #92 connected
Washer Pump #150 & #94 connected,,,
Simple
That's how I read it anyways...
Thanks for the chart. If repairing the original doesn't work I will try that path. Great reference too.
Problem solved. Thanks for the assistance and information. Cleaned out the switch of the funk, gunk, and double checked functions before putting everything back together. With the switch out I just ran a temp ground wire from the body to the switch frame to test.
The video is a little grainy.
Here is a drawing I did for a 77, wiper/washer switch to wiper/washer motor(s) .
I changed the wire colors that should represent a 78 W/O pulse or delay.
78 Corvette wiper switch problems.
