I have an '82 and my wiper interval doesn't work, i have to constantly reach down and push the button if i don't want them to go constantly on high or low. which gets pretty irritating . Can someone point me in the right direction to fix this???

 

Me too. Been living with it for 150K miles.

 

your year has a pulse relay, probably behind seat in trapdoor that controls
wiper function. look below trap door on pass side.

 

My relay made constant clicking sounds until I finally unplugged it. I haven't found a replacement. Let me know if you find a supplier.

 

Have Three Or Four Left In My Shop Inventory.

 

I may be interested in one. PM me with the info.
Thanks Steve

 

I think that relay is no longer being manufactured. There's a guy on this board who rebuilds them...

I'll repost if I can find his name.

 

Thanks!!! I'll check and see if I can find it.

 

How Much $$$ ???

 

Here is the wiring diagram


Motor
White-power to motor
Purple- low/high speed signal, taken to ground when wipers are on
Gray- High speed signal, taken to ground when wipers not on high
pink- wipers in delay stop position, grounded by switch in motor cover
black - motor ground, connected at bell housing

wiper switch
dark green- delay control, grounded in every position but delay
brown- voltage source to delay adjustment
white/black- variable voltage signal from delay adjustment
gray- instrument lamp power
purple- low/high control, grounded in every position but off
gray/black- high control, grounded in every position but high
black- ground
pink-washer control, grounded when washer button is pressed

wiper controller
dark green- delay signal, taken to ground when not in delay
brown- voltage source from wiper controller for delay adjustment
purple- low speed control, grounded while/after washer is on
white- power to motor, on except during delay stop
brown/white- power to controller
pink- washer signal, taken to ground when washer is on
pink/black- washer control, taken to ground when washer is on or
delay position control, taken to ground when wipers in delay position
white/black- delay adjustment signal

next installment will be on the wiper controller circuit.

 

here is a start to the circuit drawings



more later

 

here is the complete drawing


and the picture. I have removed the relay and the power transistor


next will be the test proceedure

Dale

 

Nice post Dale

I have done the same research as you years ago and come to the same conclusions.
Funny thing is that you live close to me! (Kelowna)

Guy's Mr Wilson has given you everything you need here to fix your delay wipers on all 78-82 corvettes. Follow the diagrams closely and work your way through them. Most likely your controller needs some repairs. Do a search for dalewilson99 on this forum for the fixes. There was also someone from the UK that listed the part numbers for the controller electronics. The costs to fix the electronics are less than $20 and are a very easy fix.
The next problem lies with the wiper motor; a pin that rotates within the motor activates the delay. There is a pink wire that is connected to the outside of the motor cover. When the pin comes around and touches the pink wire the delay starts. The pin within the motor wears against the internals, as it wears it wobbles, thus missing the contact with the pink wire, therefore no delay.
The motor is a simple fix as well, or get a new one and change the cover over to the new unit.

 

I agree with Sean82 about the delay switch in the wiper motor cover.
I rebuilt mine, it is a wear part. Going to Kelowna tomorrow!!, take wifey there for a two days.

I have tested/repaired about 10 of these controllers all had something wrong with them.

Part replacement fail rate symptoms

D1 1N914 10% ?
Q1 MPSA14 10% relay would not switch
D2 1N4148 0%
D3 1N4002 0%
D4 1N4002 0%
D5 1N4002 0%
Q3 D40C1 or MPSW45A 30% no wipers or wipers always on
ZD1 1N4735A 50% delay issues, always replace
Q5 TIP42C 10% no delay
Q6 MJH6284 60% no delay/wipers, replace
IC1 MC14011B 10% posessed wipers!!!

C1 10uf 16V Replace these on spec
C3 33uf 35V
C4 1uf 50V
C5 1uf 50V
C6 1uf 50V


Dale

 

It could be as simple as the wiper switch. Ther is a guy in Hawaii parting out an 82 I be he still has the switch and the relay. Check the parts for sale section you will find him. his name is Davyn.

 

I already bought it.

Jim

 

The wiper switch is also an easy fix if you have the patience. Take it apart, clean it and make sure the contacts are all working.

Dale, I am in Vancouver for a few days, - suggest we meet in the spring when the cars are out of storage. I could show you my cruise control fixes, if you have not already figured them out.

Too bad this post could not be made some kind of sticky, -all 78-82 vettes will require Dale’s information at some point.

 

I hook up the thing on a work bench.Red +12 volts black ground


1-Test ZD1
Between pin 14 and pin 7 of the IC there should be 6 volts. Be Careful not to short out pin 7 if you do ZD1 will be shot.

2-test the relay cct.
ground the dark green wire, the relay should switch. lift the ground relay will switch back.

3-washer control
ground the pink wire. pin 3 sould go from 6v to 12v,pin 11 from 12v to
6v, junction of R5 and Q3 should go to 12v and the purple wire should go to 0v.
remove the ground the circuit will switch back after a time delay of 5 seconds??

4-delay control
momentarially touch ground to green pin 8 of ic 6v
momentarially touch ground to pink/black, pin 8 of ic 12v

repeat ground cycle, pin 10 goes from 12v to 6 v

touch green, 12v at junction of Q4 and R15
12v at junction of Q5 R16
12v at white wire, may have to remove relay to see this change.

As always, you can send me the part and I will fix it for you.

Dale