If you desire such a device, you can modify your system along the lines of the Simm change shown in the October 1976 Roundel and wire in a switch to cut out the washer function. It is a very simple change, inexpensive, and is good for getting two or three swipes of the wipers when you want them. The disadvantage is that you get several swipes each time, whether you want more than one or not, and you have to keep pulling the lever if you want an occasional swipe in a steady light drizzle.
You can also go to the factory system in use on the 1976 2002 and earlier six-cylinder models. For more information on this, see your local dealer and Robert Murphy's excellent article on this system in the November 1976 Roundel. The advantage of this system is that it looks factory after installation. The disadvantages are that it is expensive (+$50), the sweep interval and frequency are fixed, and it may not be optimal for every situation, as I discovered on a 1976 2002.
There used to be several kits made for this purpose. I tried one made by Radio Shack a few years ago. It was unreliable while it worked and soon failed. I do not think that any of the stores like Radio Shack or Lafayette carry them any more.
Then you can buy the Heathkit system. The kit is number CH-1068 and can be ordered from the Heath Company, Benton Harbor, Ml 49022, from a Heathkit store, or by calling (616) 982-3411. For about half of what the installation of the factory system would cost, you end up with an excellent system. The kit comes with excellent, detailed instructions that can be understood by any literate adult. You will need a soldering iron and a few simple tools, but virtually everything else is included in the kit, including solder. The instruction manual is divided into three parts: determining the type of wiper system you have, wiring the kit for this type of system, and installation. From start to end, the project took about four hours. I hope that my comments can reduce that time considerably.
Page 21 in the instructions is the type of system for my 1972 2002. It is a Type I that is discussed on page 22. You should have a brown/red wire that goes to the wiper motor and tests out as outlined at the top of page 22. This means that you need to install diode D2 according to diode installation Detail B. This is very important, so turn to page 33 and cross out diode Detail A right away. A major portion of the time it took me to install the setup was spent determining that I had misread the instructions and crossed out Detail B. This resulted in several blown fuses and a high frustration level before I discovered my error!
Assembly is very simple and does not require elaboration here. Just work carefully and solder all connections well.
If your system is the same as mine you should connect the red (hot) wire to any hot line. The most convenient source in my car was the hot line to the radio, which is fused. Connect the black (ground) to any ground. Since brown wires in Bimmers are grounds, you can piggyback onto any one of these that happens to be in the area. You can run the green, white and orange wires through any one of several pre-existing holes in the firewall. I used the one the speedometer cable goes through. Connect the green wire to the aforementioned brown/red wire going to the wiper motor. Connect the white wire to the brown/red wire going away from the wiper motor. Recheck the green and white wires and ensure that you have them connected to the correct segment of the brown/red wiper motor wire. Splice the orange wire into the purple/black wire that goes to the wiper motor. You do not have to cut this wire, just splice into it. The system should now be ready for use.
When you turn on your wipers, they will work normally. When you pull back on the wiper stalk, the washers will work normally. But, when you turn the delay control knob on, the wipers will sweep intermittently at frequencies from one per second to one per minute. If the delay is on and you wish to turn on the wipers or wash, do so. The delay system will immediately shut off. There are excellent trouble-shooting directions in the instruction manual, as well as directions for varying the number of sweeps per cycle. I find that one sweep is perfect.
After eight months here in the Gulf Coast rain forests, I could not be more pleased. I prefer my system to the stock system in my wife's 1976 2002. The biggest advantage is the frequency adjustment. I installed mine to the under-dash panel nearest the hood release latch.
Author: Bill DuVal