VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1912-1928 new mystery on my '28

It was a busy weekend cleaning up the car, ripping out poor wiring from previous owners and fixing a gas leak at the bottom of the vacuum canister. What I discovered was the control on the dash for the wipers goes nowhere and was just spooled up behind the vacuum canister. And to add mystery, the wiper motor has a tiny push/pull button coming into the car through the header above the windshield. Good news, in that it works just fine. There is also no vacuum switch anywhere in the engine bay.

My question is, what the heck do I have?

Apparently you have a '31 type wiper setup on your car. The original '28 had a 1/4" vacuum line from the top of the vacuum tank to a needle valve installed in the left most hole (looking from the front seat) in the dash center section. An 1/8" metal tube runs from the valve up the drivers side windshield post and out near the left side of the wiper. A short piece of rubber hose then connects to the inlet pipe on the wiper. There is no valve on the wiper.

The '31 passenger closed cars (exc. Landau Phaeton, Cabriolet) had a vacuum tube installed in the intake manifold that ran to near the firewall, then a hose through the firewall to a tube that ran up the windshield post coming out on the left side of the wiper and a hose connecting to the wiper inlet valve. The valve is a slide valve that is controlled by a bent wire (11 bends) that rotates in a hole in the bottom of the outside front header cover, goes up over the windshield and then back down to a slot (covered by an plate) in the inside header cover. As the wire is moved side to side it pulls and pushes the valve on the wiper.

Is the mystery solved? Other than who done it?

Mystery solved. Other than the bent wire that I have not looked for, you described the setup pretty darn good. You mention the vacuum valve in the dash. what I have is more like a choke cable that goes nowhere and it does look rather new. Now that i know it too is not original, I will remove it and repurpose the hole for something. Having the cable just wound up behind the vacuum canister is just plain ugly.

I suspect it was at least 2 owners back. Previous owner was not that skilled

The choke cable goes through a hole in the opposite (right) side of the dash center section. The knob matches the one on the wiper valve. Since you don't have the wiper valve you might need to match that to the choke knob when you get a wiper valve. The wiper valve sold new today does not have the right knob for the '28 but is correct for '27 and '29-30.