Todd Z.'s Bottom Mount Wipers

By Todd Zuercher

Outside View

One of the more unusual modifications that I'm thankful for on my 1969 Ford Bronco are windshield wipers mounted on the bottom of the windshield. On 99.9% of the vehicles on the road in America, such a feature is taken for granted, but not on our classic trucks.

I grew up in Prescott, a "mile-high"(~5300 ft. elevation) city in central Arizona. Snow and rain were part of the annual regimen of Broncitis' life in those days and it became quickly apparent that the stock vacuum wipers sucked(pun intended). After several years of depending on feeble vacuum power, my dad fabricated a linkage with an electric motor on top of the windshield which mimicked the factory setup. We had this setup for several years until Dad got the itch to try something different.

Dad is an inveterate tinkerer and fabricator: holds a PhD. in backyard engineering, as I like to say. He's never enjoyed working on vehicles much; he doesn't even change his own oil. But if there's something that can be improved and requires some thought, clever design, and some fabrication, he's near the top of the list of contenders. For example, he designed and built a twin stick transfer case shifter for our Bronco a dozen years before other examples appeared in Bronco country. .

The windshield wiper setup was no different. The electric wipers on top of the windshield were a great improvement over the stock vacuum units, but you still had the problem of water and snow running down the windshield, blocking your view, as the wipers pushed the water to the top of the windshield. You can't fight gravity!

And so off to the junkyards we went! I don't remember what vehicles we pulled parts from with the exception of a wiper motor from a '66 Ford pickup and a few pieces of linkage from a Jeep Wagoneer. It must've been about a dozen vehicles though. Dad spent many hours mocking things up until he thought he had the proper sweep of the wipers figured out and then the work began.

Step one was to remove the stock radio speaker and build a bracket that mounted behind the speaker grill opening. The wiper motor was mounted to this bracket. The top two or three crossbars of the speaker grill were cut out for the linkage to pass through. Next, Dad drilled holes through the dash and windshield frame to mount the wiper arm pivots. Mounting them this way negated the fold-down feature of the windshield. But since the romance of a fold-down windshield disappears immediately after the first dirt road trip with the windshield down, no harm was done. A linkage piece was cut and welded to connect the two wiper arm pivot arms together.

Close Up of Passenger Side Linkage

The arm on the wiper motor was connected to the passenger's side wiper pivot arm with an adjustable link. Students of machine design will recognize the apparatus as a classic crank-rocker four-bar linkage. The arm connected to the wiper motor turns in a full circle(crank), activating the adjustable link. The adjustable link activates the passenger's side wiper pivot arm. The driver's side pivot arm is therefore an idler arm, of sorts. The wiper motor was then wired to a stock two speed Bronco wiper switch. This switch was replaced a few years ago with an intermittent wiper switch from a late '70s Ford F-Series pickup. The wiper arms themselves are cut-down Jeep Wagoneer units(I believe) with 13" Bosch blades on them.

Driver's Side Linkage

The coverage of the windshield is fantastic. There is some slop in the linkage pivot points and so there is occasionally some noise as the wiper blades contact the edge of the windshield molding, but this is a minimal drawback. When my dad first built the setup, he built a cover out of PVC pipe and covered it with carpet. Believe it or not, the aesthetic appearance was not cheap or unprofessional looking, but the bulbous cover was not compatible with the Protofab rollcage added several years ago. I had a smaller sheetmetal cover bent and welded together to cover the linkage. The cover currently has a layer of wrinkle-coat paint on it, but I believe I'll have it sprayed with some sort of bedliner material soon.

For those of you considering a similar setup for your truck, here are dimensions for your general information. The centerline of the driver's side pivot is 13 7/8" from the top left edge of the dash. The distance between pivot points is 23 ½". The pivot arms are 2 ½" long. The pivots are mounted on the slanted portion of the dash that's 2 ½" tall. The pivots are 1" from the intersection of the slanted portion with the main face of the dash.

Complete Linkage Without Cover

Feel free to email with any further questions.

toddz69@juno.com