I'm trying to rejuvenate the Demand Washer System on my 1970 98LS and some of the wiring has me stumped. The shop manual is black and white and honestly the pictures for this system kinda suck. I was able to decipher all but one wire, the yellow from the motor into the pump. I believe it attaches to the holding contact where the second yellow to the Demand Relay originates. I can see in the manual the green one attaches to the demand relay next to the orange one from the holding contact. It has a second yellow already preattached to the demand relay from the holding contact. The only thing left that looks like a connecting tab is on the side of the holding contact but no pictures clearly show anything in this position. I know how to read wiring diagrams so to me that location makes the most sense in accordance with the diagram but if anybody has any experience with this system please give me some backup. I don't want to get it all hooked up and not work. The cobbled-together system in place of it works well enough but I'm trying to get back to stock.

Here's some pictures:

Motor without pump, yellow and green wire.




Green attached next to orange as noted in shop manual.



Preattached yellow from holding contact to demand relay.



This is the only remaining tab of any kind so I assume this is where it attaches. This tab is on the holding contact.

 

Is the wiring schematic you have out of the Factory/Chassis Service Manual or a Chiltons/Motor manual? If you have a scanned copy of an Oldsmobile manual the resolution of images is sometimes poor.

 

Chris, that looks correct. Notice that the yellow wire that goes to the relay is electrically connected to the tab where the 2nd yellow wire is attached. I don't have my manuals available right now but will check later today to confirm.
Karl

 

It's the factory service manual. A lot of the pictures are poor due to the scans.

 

Are you using the Chassis Manual or the Fisher Body Manual? The FBM goes into a lot more detail on the programmable wiper system.

Those poor scans are the reason you should never use a reprinted or CD-ROM shop book unless there's no alternative.

 

Chasis Service Manual reprint. I had the CD ROM and printing off that was worse than the reprint of the book. I have the FBM but couldn't find anything in it about the system.

 

Even though Oldsmobile wasn't using it by 1973 this is from the 73 FBM, which has 10 pages covering the Demand Wiper and Programmed Washer systems. Maybe it will help.