Windshield Washer Pump
The last several years that VW beetles were imported to the U.S., they
had a windshield washer system that had to be one of the worst designs ever
dumped on the public. The tank was pressurized, and when you pulled
the windshield wiper control toward you, it opened a valve located in the
steering column switch assembly. It also triggered a timer relay that
ran the wiper motor for about 15 seconds.
There were several flaws in this system, including the idea of running
soapy water through all the electrical wiring in the dashboard. The
worst thing was the way they pressurized the tank, though. They used
the spare tire! There was a small hose that ran from the valve on the
spare up to the tank. That was guaranteed to drain all the air from
the spare in less than 24 hours. That system didn't even work when
the car was at the dealership!
Like almost every VW owner of those days, we just disconnected the hose
since the spare tire was a lot more important than the windshield washer,
and the washer just never squirted.
I finally got the big idea that I could make the thing work. I found
a washer pump in the J.C. Whitney catalog for about $8.50. I was sure
the valve was solenoid operated and I'd just parallel that solenoid's electrical
connection with the fluid pump. Not so, as you may have guessed (or
you've already explored the intricacies of the VW windshield washer system
and you didn't need to guess).
We'd had some trouble with the car starting a few months earlier, and
the mechanic who replaced the key switch didn't bother to hook up the tubing
back to the switch assembly. I wasn't sure what that dangling hose
was at the time, but I didn't notice anything missing, either. I started
digging around the switch, and found that two terminals did get connected
when you pulled the lever back. One side was ignition voltage, the
other went to the timer that ran the wiper motor for a few seconds to wipe
the fluid off the windshield after you had (supposedly) squirted it with
air from the spare tire.
It turned out that the tubing from the fluid tank went from the trunk
into the dashboard, through the mechanical valve in the windshield wiper
switch, then back out of the dashboard and into the fresh air box and finally
into the dual nozzle mounted just in front of the windshield. I started
pulling hose out of the dashboard, and eventually got both pieces into the
trunk where I could do some work. The shorter piece, which originally
ran from the valve to the nozzle, I discarded. The longer piece had
lots of excess for the route I wanted it to go.
I mounted the pump immediately behind and below the
tank. There it would be protected from whatever was in the trunk by
the hard plastic tank, which was designed to hold about 40 PSI, after all.
A short piece of tubing from the bottom of the tank ran to the inlet
of the pump. The rest of the hose I ran in its normal path up the side
of the trunk until I reached the dashboard. I had a little trouble
getting the hose into the fresh air box. There's a cover in the front
of the box that is fastened with several large screws. When you get
those out, the cover still doesn't want to come off because it's sealed with
some of the gooiest stuff I've ever encountered. Even after 20 years,
it's still sticky! Once I got the cover off, I found the inside of
the air box to be one of the dirtiest places I've seen on a car that didn't
get regular application of fossil lubricants. It had never been seen
by me before, and 20 years of dirt, sap, leaves, cat hair, etc. were caked
on the bottom. There is a drain from the box, and I cleaned out all of the
crud and made sure the drain was open, too.
I routed the hose through a hole in the side of the
air box and up to the nozzle.
I ran the power lead for the pump next to the hose and through the hole
in the trunk that the hose had originally gone through. I routed it
along the same path the hose had used until I got to the switch. I
used an insulation displacing crimp connector to make the electrical connection
to the wire that goes to the windshield wiper timer.
Since the washer hadn't been used for 20 years, the nozzle was plugged,
so I cleaned that out with a pin. Once the nozzle worked, I discovered
that it missed the windshield completely! It turns out that the nozzles
can be aimed (the service manual shows that) by sticking a pin in the hole
and moving the nozzle's direction so it's where you want it.
I put the trunk and dashboard back together and now have a working windshield
washer.
What I'd do Different Next Time
I'd probably buy a better pump. The first few times I tried it,
the washer worked just fine. Then I was driving my boss around one
day and decided to show it off and the #%^$@#! thing didn't work. It
turns out that the pump doesn't always start when you apply voltage to it.
This project cost less than $20 total for parts, and another few bucks
might mean a more reliable pump.
I'd also mount it a little higher and further back. It's not as
well protected as I'd hoped, although I don't believe there's been any damage
to it because of its location.
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