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914World.com _ 914World Garage _ Intermittent wiper not working
Posted by: michaelmoo Sep 15 2010, 04:26 AM
Ok I have the intermittent relay and a washer pump on my car. First ever thing is wired correctly and making good contact. Second, I know the order of the wiper switch: all the way down is intermittent, then off, then slow, then fast (well faster than slow…). Pulling the switch you get like 4 or 7 swipes and the pump comes on. That is how it is suppose to work.
Here is what I get: all the way down is nothing, then off, then slow, then fast (well faster than slow…). Pulling the switch I get the 4 or 7 swipes and the pump comes on.
Thoughts? If the relay was bad would the 4 or 7 swipes still happen with the pump?
Mike
Posted by: vsg914 Sep 15 2010, 05:56 AM
Since 914's did not come with intermittant wipers, I can't possibly know why yours don't work.
Posted by: 914Sixer Sep 15 2010, 06:33 AM
Pull your steering wheel and make sure all the 4 screws that hold the TS and Wiper switches are tight. Grounding for the the switch is through the screws. I can remember which one. Left bottom I think. Relay may have gone bad, I may have one you can test with.
Posted by: Bartlett 914 Sep 15 2010, 06:50 AM
You cannot have both intermittent wipers AND a washer pump. Disconnect the washer pump and you will see the intermittent wiper function work. The problem is the resistance of the washer pump changes the timer function in the intermittent wiper relay.
Posted by: michaelmoo Sep 15 2010, 07:16 AM
Mark,
Thanks. I will try unhooking the pump and see it that works. Car was orig my Dads and he wired in a 914-6 pump many moons ago. I added the intermit on it. I read on one thread here that someone had both when they wired it up. And if it was on here it has to be true... 
Mike
Posted by: John Jentz Sep 15 2010, 08:57 AM
Since 914's did not come with intermittant wipers, I can't possibly know why yours don't work.
Not true, it was an option.
Posted by: Tom_T Sep 15 2010, 10:08 AM
And any dealer could install one for a buyer/owner by adding the relay under the front lid/cowl & snapping off the retent tab to allow the switch to move full down. This means that all late (column wiper switch) 914s were pre-set-up for intermittent wipers (i.e.: all column switches were set up for it), but I don't know about the early dash switches.
Michael - try Jeff Bowslby for other possibilities if the above doesn't work, since he makes a repro relay/wiring set-up like the factory OE one for folks like us to add. He may have some other thoughts on what's up with yours.
Posted by: jim_hoyland Sep 15 2010, 10:29 AM
My washer works the stalk is pulled back, like you stated above; and I have a working intermittant function on the bottom setting. I'm wondering if anyone knows how to bench test the Intermittant Relay---like one can with a regular relay ??
Posted by: markb Sep 15 2010, 03:38 PM
You cannot have both intermittent wipers AND a washer pump. Disconnect the washer pump and you will see the intermittent wiper function work. The problem is the resistance of the washer pump changes the timer function in the intermittent wiper relay.
I put in a pump years ago, and later added the intermittent, but never did get it to work. Maybe this is why.
Posted by: Bartlett 914 Sep 15 2010, 06:25 PM
You cannot have both intermittent wipers AND a washer pump. Disconnect the washer pump and you will see the intermittent wiper function work. The problem is the resistance of the washer pump changes the timer function in the intermittent wiper relay.
I put in a pump years ago, and later added the intermittent, but never did get it to work. Maybe this is why.
I have done a lot of work on this project. The intermittent relay has 3 modes. Off, on for several seconds and on for 1 second switching off for about 5 seconds.
The first is obvious. We need to turn off the wipers. The control wire is the brown with a black stripe. In the off position it is held at ground. This connection is the one from the mounting screw that holds in the wiper switch.
Moving to the intermittent position (full down) this connection is open. In this position the connection must be greater than 15K ohms. In this position, the relay has the on for a second and off for 5 or so seconds. When it switches on for a second, the wipers move out of the park position. They continue until they are again parked and wait for the next pulse from the intermittent relay. Because the control wire is open for this mode, if the screw is not tightly holding in the wiper switch, we can get ghost wipes.
The third position is +12 volts when pulling back on the wiper switch. Pulling back opens the valve for washer solvent flow and applies +12 to the intermittent relay. The relay will hold as long the 12 volts is applied and the wipers will operate continuous. When the 12 volts is removed, the relay will hold for a few seconds longer running the wipers for several additional sweeps.
Because the intermittent mode uses an open condition and if we install a washer pump, the resistance of the washer motor acts as a ground. Therefore the intermittent mode will not work. The open must be greater than 15k and a washer pump is around 50 ohms.
I was just able to make both modes work on my car. I installed a circuit card that has a relay, 2 transistors and 3 resistors. The input impedance for this circuit is greater than 27 K ohms. This allows all functions to work.
Posted by: michaelmoo Sep 16 2010, 03:57 AM
Mark,
Do you have pictures of the circuit card? I'd love to have both working.
Mike
Posted by: 76-914 Sep 16 2010, 08:17 AM
Thanks Mark. I had converted to an electric pump and had lost my intermittent controll in the process. Fixing it was on my to do list, but no longer. I would have been chasing a ghost. 
Posted by: Bartlett 914 Sep 16 2010, 08:41 AM
Mark,
Do you have pictures of the circuit card? I'd love to have both working.
Mike
Here is a drawing. The card is installed in the car so no pictures of my work. The relay is a Radio Shack PC relay with a 5A contact. The input is the Brown / Black wire from the wiper switch. It is connected near where it goes to the intermittent relay. The washer pump is grounded on one side. The output of the relay provides 12 volts.
I should note I forgot the suppression diode across the relay coil in the drawing. Place the cathode to the +12 volt side and the anode on the other side of the coil.
Posted by: John Jentz Sep 16 2010, 08:41 AM
You cannot have both intermittent wipers AND a washer pump. Disconnect the washer pump and you will see the intermittent wiper function work. The problem is the resistance of the washer pump changes the timer function in the intermittent wiper relay.
I put in a pump years ago, and later added the intermittent, but never did get it to work. Maybe this is why.
I have done a lot of work on this project. The intermittent relay has 3 modes. Off, on for several seconds and on for 1 second switching off for about 5 seconds.
The first is obvious. We need to turn off the wipers. The control wire is the brown with a black stripe. In the off position it is held at ground. This connection is the one from the mounting screw that holds in the wiper switch.
Moving to the intermittent position (full down) this connection is open. In this position the connection must be greater than 15K ohms. In this position, the relay has the on for a second and off for 5 or so seconds. When it switches on for a second, the wipers move out of the park position. They continue until they are again parked and wait for the next pulse from the intermittent relay. Because the control wire is open for this mode, if the screw is not tightly holding in the wiper switch, we can get ghost wipes.
The third position is +12 volts when pulling back on the wiper switch. Pulling back opens the valve for washer solvent flow and applies +12 to the intermittent relay. The relay will hold as long the 12 volts is applied and the wipers will operate continuous. When the 12 volts is removed, the relay will hold for a few seconds longer running the wipers for several additional sweeps.
Because the intermittent mode uses an open condition and if we install a washer pump, the resistance of the washer motor acts as a ground. Therefore the intermittent mode will not work. The open must be greater than 15k and a washer pump is around 50 ohms.
I was just able to make both modes work on my car. I installed a circuit card that has a relay, 2 transistors and 3 resistors. The input impedance for this circuit is greater than 27 K ohms. This allows all functions to work.
Can you explain how you powered the pump so it caused this condition. I want to add the 911 pump and thought of replacing the water switch with a micro switch and separate 12v and grd at the pump.
Posted by: Bartlett 914 Sep 16 2010, 08:57 AM
You cannot have both intermittent wipers AND a washer pump. Disconnect the washer pump and you will see the intermittent wiper function work. The problem is the resistance of the washer pump changes the timer function in the intermittent wiper relay.
I put in a pump years ago, and later added the intermittent, but never did get it to work. Maybe this is why.
I have done a lot of work on this project. The intermittent relay has 3 modes. Off, on for several seconds and on for 1 second switching off for about 5 seconds.
The first is obvious. We need to turn off the wipers. The control wire is the brown with a black stripe. In the off position it is held at ground. This connection is the one from the mounting screw that holds in the wiper switch.
Moving to the intermittent position (full down) this connection is open. In this position the connection must be greater than 15K ohms. In this position, the relay has the on for a second and off for 5 or so seconds. When it switches on for a second, the wipers move out of the park position. They continue until they are again parked and wait for the next pulse from the intermittent relay. Because the control wire is open for this mode, if the screw is not tightly holding in the wiper switch, we can get ghost wipes.
The third position is +12 volts when pulling back on the wiper switch. Pulling back opens the valve for washer solvent flow and applies +12 to the intermittent relay. The relay will hold as long the 12 volts is applied and the wipers will operate continuous. When the 12 volts is removed, the relay will hold for a few seconds longer running the wipers for several additional sweeps.
Because the intermittent mode uses an open condition and if we install a washer pump, the resistance of the washer motor acts as a ground. Therefore the intermittent mode will not work. The open must be greater than 15k and a washer pump is around 50 ohms.
I was just able to make both modes work on my car. I installed a circuit card that has a relay, 2 transistors and 3 resistors. The input impedance for this circuit is greater than 27 K ohms. This allows all functions to work.
Can you explain how you powered the pump so it caused this condition. I want to add the 911 pump and thought of replacing the water switch with a micro switch and separate 12v and gnd at the pump.
There are different switches. Earlier ones did not have a contact. The connector for the switch has 5 positions. If one is open then the switch is an earlier one and this won't work. If you do not have the intermittent relay, you can directly connect the Brown ? Black wire to a washer pump. One side of the pump is grounded. The wiper switch will supply 12 volts at the Brown / Black wire when pulling back on the stalk. If you want both intermittent wipers and an electric washer pump. install the intermittent relay and wiring harness and build the small circuit I provided to drive the washer pump.
Posted by: Bartlett 914 Sep 17 2010, 08:11 AM
Here is a copy of what I made for having both intermittent wipers and electric washer pump. The relay drives the pump.
Attached image(s)
Posted by: Bartlett 914 Sep 22 2010, 07:55 AM
I found an error in my schematic. I added a resistor from the base of Q2 to ground. Omitting this resistor damages Q2. The drawing has been updated.
Attached thumbnail(s)
Posted by: motomadness1947 Sep 25 2010, 02:14 PM
error
Posted by: motomadness1947 Sep 25 2010, 02:14 PM
error
Posted by: motomadness1947 Sep 25 2010, 02:15 PM
You say there are two different switches and the early one does not have a contact. What do you mean or where does it not have a contact.
My problem is similar but different then the above. My switch seems to have three positions bottom which I would assume should be off is intermittent, next up is slow, next up is fast. Unless I pull the relay, they will not stop.
I only have had the car for a couple of months and the wipers did not work. I found the problem was someone had pulled the number 8 fuse. When I replaced it the above happened. Any ideas. do I need to replace the wiper switch, is mine an onld version in a newer car? My car is a 74 built in december of 73
Thank you
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