Intermittent Wiper mod from fixed to variable delay
- Thread starter bgennette
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I am really interested in this wiper relay. Mine works, well intermittently, and would love to go solid state. I will see if I can put together a wiring diagram for my 90A01 motor driven relay. It is currently on my 82' BJ42LX. Hopefully we can work together to create an adjustable solid state replacement for it.
- Thread starter
- #25
Universal Circuit for 60
This is the circuit from the 85940-90A04 (1987 to end) Int Controller drawn on strip-board, with connections to a standard automotive relay to utilize the existing Toyota switches and wiring. As it is over 25 years old I hope Toyota will not complain about reverse engineering it today.
The circuit schematic can be seen in the first post to this thread. There is only one track cut on this board at strip 4, column 4.
The numbers at the left are the pin numbers for the Plug under the dashboard -
Park = Pin4, S2 = Pin2, +V = Pin3, Motor = Pin1.
The numbers on the right are the pin numbers for a Single Pole, Double Throw relay.
85 & 86 operate the relay, 30 is common out, 87 is normally opened, 87A is normally closed.
The lettered points are where new parts connect -
Sn & 0V are for using a New Switch (only required when adding Int to the rear wiper; 0V goes to chassis while the new switch goes between Sn and S2), P & P are to/from the Potentiometer (that sets the delay time).
The circuit is very small (less than 25mm x 25mm), so it can easily be glued to the side of a (plastic) relay.
The rear wiper (in the 60s) doesn't use a relay and employs a non-standard switching method for the park function. To add a delay a new switch should be used to allow the Toyota park circuit to work with this circuit. (A Pot with a switch built in is a good choice).
When the pot is set to 0 the 22k resistor gives a delay of about 2s. Adding 100k (total 122k) gives about 15s between wipes - this is fine for the windscreen. If a 250k (total = 272k) is used the delay can be stretched to over 1m - fine for a rear window. Note - when used for a rear wiper there will always be a short delay between wipes unless more complicated switching is added.
Component Values -
R1 = 22K, R2 = 2.2K, R3 = 47K, Pot = 100K to 250K
C1 = 100uF electrolytic (must be NON-Polarized type as it swings from +15 to -8V! Working voltage >=25V)
C2 = 100nF
D1 = 1A type like 1N4004
D2 = small signal type like 1N918
Transistor = NPN type, moderate power like BC337 (NOT PNP type BC327
like in the picture)
Relay = 12V SPDT, coil type 90 ohms (<200mW)
Stripboard = 9 strips x 8 holes
Total cost <$15
[note many stores will rip you off for the electrolytic cap and the switching pot, they should be under $2 each but expect $10 in single quantities for newbys
Stripboard also seems to be overpriced (but can often be 'found' in salvageable sizes in older electronics)]
I'll be trialling this soon, pictures to follow.
bye.
This is the circuit from the 85940-90A04 (1987 to end) Int Controller drawn on strip-board, with connections to a standard automotive relay to utilize the existing Toyota switches and wiring. As it is over 25 years old I hope Toyota will not complain about reverse engineering it today.
The circuit schematic can be seen in the first post to this thread. There is only one track cut on this board at strip 4, column 4.
The numbers at the left are the pin numbers for the Plug under the dashboard -
Park = Pin4, S2 = Pin2, +V = Pin3, Motor = Pin1.
The numbers on the right are the pin numbers for a Single Pole, Double Throw relay.
85 & 86 operate the relay, 30 is common out, 87 is normally opened, 87A is normally closed.
The lettered points are where new parts connect -
Sn & 0V are for using a New Switch (only required when adding Int to the rear wiper; 0V goes to chassis while the new switch goes between Sn and S2), P & P are to/from the Potentiometer (that sets the delay time).
The circuit is very small (less than 25mm x 25mm), so it can easily be glued to the side of a (plastic) relay.
The rear wiper (in the 60s) doesn't use a relay and employs a non-standard switching method for the park function. To add a delay a new switch should be used to allow the Toyota park circuit to work with this circuit. (A Pot with a switch built in is a good choice).
When the pot is set to 0 the 22k resistor gives a delay of about 2s. Adding 100k (total 122k) gives about 15s between wipes - this is fine for the windscreen. If a 250k (total = 272k) is used the delay can be stretched to over 1m - fine for a rear window. Note - when used for a rear wiper there will always be a short delay between wipes unless more complicated switching is added.
Component Values -
R1 = 22K, R2 = 2.2K, R3 = 47K, Pot = 100K to 250K
C1 = 100uF electrolytic (must be NON-Polarized type as it swings from +15 to -8V! Working voltage >=25V)
C2 = 100nF
D1 = 1A type like 1N4004
D2 = small signal type like 1N918
Transistor = NPN type, moderate power like BC337 (NOT PNP type BC327
like in the picture)Relay = 12V SPDT, coil type 90 ohms (<200mW)
Stripboard = 9 strips x 8 holes
Total cost <$15
[note many stores will rip you off for the electrolytic cap and the switching pot, they should be under $2 each but expect $10 in single quantities for newbys
Stripboard also seems to be overpriced (but can often be 'found' in salvageable sizes in older electronics)] I'll be trialling this soon, pictures to follow.
bye.
Last edited:
This is the circuit from the 85940-90A04 (1987 to end) Int Controller drawn on strip-board, with connections to a standard automotive relay to utilize the existing Toyota switches and wiring. As it is over 25 years old I hope Toyota will not complain about reverse engineering it today.
The circuit schematic can be seen in the first post to this thread. There is only one track cut on this board at strip 4, column 4.
View attachment 607912
The numbers at the left are the pin numbers for the Plug under the dashboard -
Park = Pin1, S2 = Pin2, +V = Pin3, Motor = Pin4.
The numbers on the right are the pin numbers for a Single Pole, Double Throw relay.
85 & 86 operate the relay, 30 is common out, 87 is normally opened, 87A is normally closed.
The lettered points are where new parts connect -
Sn & 0V are for using a New Switch (only required when adding Int to the rear wiper; 0V goes to chassis while the new switch goes between Sn and S2), P & P are to/from the Potentiometer (that sets the delay time).
The circuit is very small (less than 25mm x 25mm), so it can easily be glued to the side of a (plastic) relay.
The rear wiper (in the 60s) doesn't use a relay and employs a non-standard switching method for the park function. To add a delay a new switch should be used to allow the Toyota park circuit to work with this circuit. (A Pot with a switch built in is a good choice).
When the pot is set to 0 the 22k resistor gives a delay of about 2s. Adding 100k (total 122k) gives about 15s between wipes - this is fine for the windscreen. If a 250k (total = 272k) is used the delay can be stretched to over 1m - fine for a rear window. Note - when used for a rear wiper there will always be a short delay between wipes unless more complicated switching is added.
Component Values -
R1 = 22K, R2 = 2.2K, R3 = 47K, Pot = 100K to 250K
C1 = 100uF electrolytic (must be NON-Polarized type as it swings from +15 to -8V! Working voltage >=25V)
C2 = 100nF
D1 = 1A type like 1N4004
D2 = small signal type like 1N918
Transistor = NPN type, moderate power like BC337 (NOT PNP type BC327
.
elay = 12V SPDT, coil type 90 ohms (<200mW)
Stripboard = 9 strips x 8 holes
Total cost <$15
[note many stores will rip you off for the electrolytic cap and the switching pot, they should be under $2 each but expect $10 in single quantities for newbys
I'll be trialling this soon, pictures to follow.
bye.
sorry, i don't understand what you mean by park function or park circuit. could you explain please. i would like to get it working. thanks
Most wipers have a function that feeds power to the motor AFTER you turn the switch to 'off', so the wipers will return to their parked position. Sometimes a cam on the motor is used to open a contact once the wipers reach the park position, fully turning off the motor.
- Thread starter
- #28
Inside the wiper motor gearbox is a cam that operates a 3 pole, 2 position switch.
In the park position it connects pin 1 (on the intermittent circuit) to 0V (ground).
While ever the wiper motor is running pin 1 is connected to +12V. The relay (in its normally closed position) in the intermittent circuit passes this 0V or +12V to the wiper motor so it can keep running when the wipers are turned off (until it reaches the park position).
This is how the intermittent works, it supplies power through the relay for just a second, then the relay switches over to the park circuit to complete just one wipe. After the delay set by the timing capacitor and resistor the circuit triggers again.
See the circuit diagram in the first post.
bye.
In the park position it connects pin 1 (on the intermittent circuit) to 0V (ground).
While ever the wiper motor is running pin 1 is connected to +12V. The relay (in its normally closed position) in the intermittent circuit passes this 0V or +12V to the wiper motor so it can keep running when the wipers are turned off (until it reaches the park position).
This is how the intermittent works, it supplies power through the relay for just a second, then the relay switches over to the park circuit to complete just one wipe. After the delay set by the timing capacitor and resistor the circuit triggers again.
See the circuit diagram in the first post.
bye.
Hi there, I have variable intermittent on both the front and rear wipers on my 61.
I always thought it was factory fitted, but mabe its not? there are two control boxes under the dash.
I will take a photo of one tomorrow for you guys...
I always thought it was factory fitted, but mabe its not? there are two control boxes under the dash.
I will take a photo of one tomorrow for you guys...
I have a 81 hj60, 24volts. I am eager to find a solution like this for som fine tuning of INT,.
I guess things are slightly different on the 24v side...
I guess things are slightly different on the 24v side...
- Thread starter
- #31
Hi TLC Norway,
The circuit should be the same for 24V, BUT the bi-polar capacitor should be at least 50 working Volts and the relay has to be a 24V type. R1 may have to be reduced a little (10-12K) to provide the shorter delays.
I hope to (finally) test this over the weekend . . . .
bye.
The circuit should be the same for 24V, BUT the bi-polar capacitor should be at least 50 working Volts and the relay has to be a 24V type. R1 may have to be reduced a little (10-12K) to provide the shorter delays.
I hope to (finally) test this over the weekend . . . .
bye.
Hi Bgennette,
Thanks a lot for the details! I am trying to get the rear wiper intermittent but what a headache this it becoming
I thought to just put a box inbetween the existing wire in the rear.
24v in, 24v out and ground and fixed
but no, ...
So I found a 24v red box 85940-90A05 under my steering wheel, it is not on your list.
This is the after 1985 model that replaced the one with the sprockets and stuff!
And I thought 85940-26010 would get me there but this is just another relay that I now dont even know what it does:
Last week I was at Waterloo so I understand how Napoleon felt
My thread on this because I thought more people would like an interval rear wiper;
https://forum.ih8mud.com/diesel-tec...lay-rear-wiper-85940-26010-a.html#post8239642
Thanks a lot for the details! I am trying to get the rear wiper intermittent but what a headache this it becoming
I thought to just put a box inbetween the existing wire in the rear.
24v in, 24v out and ground and fixed
but no, ...So I found a 24v red box 85940-90A05 under my steering wheel, it is not on your list.
This is the after 1985 model that replaced the one with the sprockets and stuff!
And I thought 85940-26010 would get me there but this is just another relay that I now dont even know what it does:
Last week I was at Waterloo so I understand how Napoleon felt
My thread on this because I thought more people would like an interval rear wiper;
https://forum.ih8mud.com/diesel-tec...lay-rear-wiper-85940-26010-a.html#post8239642
Last edited:
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