I like vacuum wipers because they add "character" to our old trucks. Yes, I know the limitations and would probably tire of their shortfalls if my stovebolt was a daily driver in a wet climate.
Trico, the maker of our wipers, also knew the shortfalls and they provided an optional vacuum pump. I don't believe these were a GM option, so they would have been "aftermarket".
I found this on the firewall of my COE

http://s1116.photobucket.com/user/1950Cabover/media/IMG_0052_zps01521464.jpg.html?sort=3&o=20

It is in series, so to speak, with the vacuum hose and consists of a 6 volt motor that drives a vacuum pump. There is an electical switch that detects loss of vacuum and then kicks in. This is what it looked like during the restoration, in the same place on the firewall.

http://s1116.photobucket.com/user/1950Cabover/media/IMG_0700_zps8f39f3e5.jpg.html?sort=3&o=18

I wired a simple on/off switch below the dash because the pump will come on as soon as you turn the key. I will turn the switch on when I am driving in the rain but it only runs when needed, as in going uphill or accelerating. It completely eliminates loss of wipers when going uphill and is capable of running the wipers with the motor off, all by itself. I tested it and it produces about 11 inches of mercury vacuum. I have seen very few of these on Ebay and they tend to be pricey but mine just happened to come with the truck.

Kent




Last edited by Lightholder's Dad; 03/19/2014 2:53 AM. Reason: Grammar!
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