VCCA Home Forums TECHNICAL - 1945 AND NEWER 1946-1948 Rear Wiper set-up

there are no knock outs anywhere on the dash that I am aware of....

Johnny on the dash pictured, It appears there are more holes than accessary switches...What do you think???I would think holes 2-3-4 from the right would be heater, defrost and fog. I do use the bigger hole on the left next to the hood release for my washer button...What other switches for 46-48 that would fit in the holes???

What type of switch is used on a convertible?

What type of switch was used for accessory under hood light and/or trunk light ????

Both of those switches are Mercury types and are located in the two devices.

Perhaps the 4th hole is for the back up light switch if it is not equipped with the automatic switch under the hood on the shift mechanism.

The top mechanism is electric and is activated with a rather husky switch located on the lip of the dash. (I don't think it uses the 4th hole).

From left to right:
1st hole is for mounting the dash, of course...
2nd hole with smaller hole in front of it is for the hood release.
3rd large hole is for windshield washer unit switch or rear wiper switch.
4, 5 & 6th holes (triangular pattern) for convertible switch bracket.
7, 8, 9 & 10th holes for defroster, heater, fog and fresh air unit switches. fresh air unit instructions tell you to use the hole nearest the steering column.
11 & 12 slotted holes for steering column mounting of course....

Note: See instructions specific to Chevrolet only, Not generic GM for the rear wiper unit and it says to use the lower factory hole on the dash if unused, and states it is an alternate location. The true location of the switch is on the face of the dash as shown.



Under hood light and trunk light have built in mercury switches and only require power and grounding. the original back up light switch mounts to the shift linkage under the hood.

WOW, Johnny, great job. Thanks

Is their some way to put those sheets on your site in a larger size?

Johnny more then I expected...I never thought about the convertible switches...I knew you were the Accessary King

So I found the vacuum switch for the rear wiper (no knob yet) and got some vacuum hoses (the rear assembly takes two different sizes hoses.) The odd thing is that, when I got the car, the rear wiper assembly was all mounted, including the motor, and there is a T fitting in the main vacuum line to the front wipers, but the branch hose is plugged. I could also find no evidence that any holes were drilled to accommodate the hoses. So it looks like someone originally started to assemble the rear wiper, but for some reason, stopped.

I hooked up the switch and hoses, attached them to the rear wiper and...nothing.... Took the motor apart and it actually looked pretty good in there - lots of grease, maybe too much, so I cleaned it out well, made new gaskets and applied brake fluid to all the areas. The paddle looked OK to me - the leather seemed soft and supple and moves back and forth in the motor with a little bit of friction. The directional switch seems to work well like it should, sending the paddle back in the other direction. Put it all back together, hooked it up and ... nothing. I heard some air escaping from the unit - hard to tell from where exactly. It's almost like I'm missing something - so close, but no cigar yet...

So I wrote Wiperman asking if I could send the motor to him for a rebuild, etc..., and he wrote back saying he won't do the rear wiper motors because "they're poorly designed units that have a parking valve that simply does not work." I haven't contacted Filling Station or Chevsof40s yet about their service.

Now I'm stumped as to my next choice. I doubt I could find a good rebuilt wiper motor alone (some guy on eBay wants $750 for the entire unit!)

I'd like to know if anyone has the rear wiper option and how it runs for them. I also wonder if it's possible to switch to a 6V motor? Has anyone done this to a rear wiper? My first choice is to stay with the vacuum and keep as original as possible, but if I can't get it to work, it's not of much use as is.

He eliminates the parking feature on the front wiper motor when he rebuilds it. The park is nothing less than a built-in vacuum leak. That might be the sucking sound you hear from the rear. Pinch closed the small hose and see what happens, if anything.

So CONWAYDE,have you drilled holes in your car yet???

NO! Not yet, Chef-Chevy - I'm actually taking the motor apart again and seeing if I missed something. I think the paddle is more worn than I believed and rubbing too hard against the case. I assume that it has to move in there fairly easily to just be powered by vacuum yet with some resistance, and mine was resisting even when I was moving it with pliers. The leather, or cloth, or whatever material makes up the paddle now looks worn to me. I can't determine if it was one piece and wrapped around the paddle and just worn to seem like it's two pieces, or if it was actually two pieces. I'm going to plug off the parking brake side, which means that, if I do get it to work, I'll only have to run one hose to it. I'll update as I figure this out.

No turning back after you drill those holes....I have many accessories, but I must admit there are some I still second guess their installation

So, after working on my vacuum motor some more, including using silicone to stop any leaks, etc..., I still couldn't get it to work. Phooey.

So, somebody up there must like me, because I found a NOS motor on Fleabay and it arrived today. And what a sight to behold - brand new and shiny. At first it seemed very stiff, so I added some oil and kept working it in there slowly and it finally came around. I attached the switch and hoses just to get a test run, and Holy Mackerel, it works! Even the parking stop works without any apparent leaks.

Now, Chef-Chevy, comes the tough part - drilling the holes for the hoses. That part is scaring me, but I guess it has to be done. I had put it off until I was sure I could get the whole system working. I no longer have an excuse now.

The only thing I'm missing now is the correct plastic knob, so if anyone has an extra one, please let me know. Otherwise, in the meantime, I have to use a reproduction '41 Ford (horrors!) wiper knob...

So I finally built up the courage to drill some holes in my Fleetline - four of them, in fact. Following the instructions that Modiol and Conv48 posted (thanks guys) I think I drilled them in the proper places. I ran the hoses along the frame, hooked them up to the motor, then the switch, and unbelievably, the rear wiper came to life! When I turned it off, the parking feature worked and it returned to rest. No leaks for the moment. It was a sight to behold, I'm telling you...

Now, they only thing I'm missing is the elusive plastic knob that goes on the switch. I've posted a want in the Parts Wanted section, but I'll also mention it here - If anyone has one they don't need or want, please let me know.

If you DO already have one and don't want to part with it, and trust me enough to loan it to me, I can make a mold from it, and cast a repo for myself and others that may need one too (I'm actually pretty good at doing this) - and several for you also, if you want. The original would not be harmed or damaged at all in making the mold and would be returned to you in the same condition.

Wow Congrats...

Hey Chef-Chevy - you have the window Washer option, correct? What's the knob like on that - is it similar to the rear wiper knob? Is it Trico or GM made?

I believe it is Trico...It is unlike the stock front wiper valve knob...It is a push button which opens and allows air to flow

Here's the valve "switch" for the window washer I am referring to




I would think a wiper valve and knob would be more what you would be looking for

Yeah, this isn't anything like the knob for the rear wiper - look at the pics on the first page of this post and you'll see what I mean.