1956 Power Top Limit Switch Mechanicals

**Mike M.** · June 18, 2014, 07:19 AM

Re: 1956 Power Top Limit Switch Mechanicals

i restored my early 56 with power top about a year ao. the toggle switch connected to the bow assembly via a wire cable on this 56. i sold the car to Hendricks so photos not available. perhaps dale ledbetter can photo it for u. regards,mike

**Richard M.** · June 18, 2014, 08:24 AM

Re: 1956 Power Top Limit Switch Mechanicals

That's going to solve a big mystery for us Mike. Thanks. John Baldwin and I were scratching our heads yesterday trying to figure it out. He couldn't recall the early PT stuff. So he and I looked at the '57 Super Sport up close yesterday morning to check it's top limit switches still in the car. Styling removed the ST frame/rag but never took the power top stuff out when they built it in late '56, even the pump, wiring and cylinders were left in. They just painted around that stuff. The SS is '56 #1589 so it's a few thousand earlier than the '56 I have here, which BTW is his. He has about a dozen Corvette projects he's working on and I'm helping him with this '56. The SS has the identical toggle switches in the well just like this one, and that little toggle has the hole in it. BTW it's a awesome car. Much fun to touch and look at.

Here you can see the toggle switches, still there. Pics long after it got wrecked, from the 90's before he restored it.
57SS_Before0039.jpg 57SS_Before0038.jpg

Do you recall if the cable from the toggle went to the area where those 2 threaded holes are in the arm, or was it a different spot? I don't know Dale, is he on here and has email/PM access? If so I'll drop him a email.

I discovered late last night that this soft top frame is not a '56/'57 frame. It's the later '59+ type without the split adjustable upper horizontal side window frame. I wonder if that'll be a issue with this one.

But my '59 has a '56 top frame and I see no major differences in that arm area. Both years' frames have those 2 threaded holes in the same place on the arm.

Thanks,
Rich

**Cecil L.** · June 18, 2014, 10:09 AM

Re: 1956 Power Top Limit Switch Mechanicals

I owned VIN 2607 (number 1607) from 72 to 96 and I recall that it was a solid wire link, not a cable, on the toggle.
I think I have an extra switch left over from another car somewhere, and I seem to recall the wire was still attached.
If I find it, I'll let you know.
Cecil

**Richard M.** · June 18, 2014, 10:32 AM

Re: 1956 Power Top Limit Switch Mechanicals

Thanks Cecil that'd be great.

**Richard M.** · June 20, 2014, 06:49 AM

Re: 1956 Power Top Limit Switch Mechanicals

Someone got me a photo of the switch. It's a bracket mounted to the frame arm's 2 threaded holes, and a small diameter rod connects to the bracket and passes through the hole in the toggle switch. I'll be able to make this up easily.

Thanks for the leads.

I got the system running last night on the bench. This after discovering the prior rebuilder of the pump motor had it assembled upside down so it would never pump. After fixing it, it works well on the bench. Will be installing back in the car soon, after re-installing the soft top to correct some installation flaws.

Video of the bench test...............

http://www.youtube.com/attribution_link?a=JEHzuNjPDFI&u=/watch%3Fv%3DeIA0QGl2gOw%26feature%3Dem-upload_owner

Rich

**Gerry P.** · June 20, 2014, 12:44 PM

Re: 1956 Power Top Limit Switch Mechanicals

Thanks Rich and everyone else. This thread and video should prove helpful when I get around to diving into my '57's power top mechanism in an attempt to get it operational again.
Gerry

**Richard M.** · June 20, 2014, 01:14 PM

Re: 1956 Power Top Limit Switch Mechanicals

Gerry, Just a FYI.....your '57 will likely have the micro switches and a different setup of links for those limit switches. There will be a arm going down next to the Pass seat where the switches moved to in '57. Also the limit switches in the trunk changed to micro switches, and other subtle differences in the mechanism and wiring.

When I get time I'm hoping to document this. Dave Zuberer has already started working on one with some of my info from this thread on CF.

Rich

**Richard M.** · June 21, 2014, 06:16 AM

Re: 1956 Power Top Limit Switch Mechanicals

A nice Fellow Member where I got the photo of the toggle switch said.... feel free to post the picture of the "top fully up" limit switch. Here it is.....

1956TopLimitSwitches.jpg

**Garry B.** · June 21, 2014, 07:51 AM

Re: 1956 Power Top Limit Switch Mechanicals

Rich, as if you don't have enough challenge already with this power top, if I recall, NCRS and BG judges require this top to cycle (from down to up or up to down including closing of deck lid on both) within twenty seconds or less. During operations check mine typically accomplished this in sixteen seconds. Of course this only happened on every other Friday between 2 and 4 pm while wearing shorts, a tee shirt, hat on backwards, holding my tongue just right while chanting "c'mon baby, c'mon baby!" I have more pictures should you need anything else. Good luck!
Garry Barnes 18531

**Richard M.** · June 21, 2014, 10:15 PM

Re: 1956 Power Top Limit Switch Mechanicals

Gary, That photo was great, thanks again.....

Wow 16 seconds on a good day seems very short to me. But I've never witnessed a real one...until now.

This car isn't being fully restored for judging. It's going to be a driver.

Rich

**Richard M.** · June 22, 2014, 07:57 AM

Re: 1956 Power Top Limit Switch Mechanicals

I did some work on the motor and pump yesterday to try to optimize it's operation.....Maybe I can get it running best with this plan.

I removed the magnet and field coil to rewire it. Old wires were damaged and bare in a few spots. I also worked on the armature commutator and dressed it with some 1000 grit while spinning on my lathe. I then put some 400 grit paper around it and installed in the end frame, loaded the brushes, and rotated to get the brushes conformed to the commutator better. Originally only about 1/3 of the brush set was contacting. Much better now, nice curved brush contacts.

Since I had it all apart again waiting for the new rebuild kit from Hydro-E-lectric due tomorrow, I decided to remove all of the black paint from the assembly and do it up like originally plated. I used Eastwood Silver Cad. Not bad. Too bad all my work is going to covered up by the division panel.

I have also acquired 4 relays to add into the circuit to the solenoids. This is to reduce the current through about $1500 worth of safety and limit switches in the system. I suppose this mod wouldn't even get a deduct because they'll be hidden away behind the panel too(unless they put a inductive ammeter on the flimsy 16 gauge wiring in the harness, reading a few hundred milliamps versus 12-15 amps). Shhhh, don't tell anyone.

A few pics of the processes........Rich

P6210015.jpg P6210023.jpg P6210031.jpg P6210038.jpg

edit.....P.S. BTW, I was rummaging through my 1958 & 1961 Passenger car shop manuals, and found the diagram of the motor and pump assembly. I overlooked that the other day and someone mentioned to look there. It's in the body section under folding top. Derrrr! Wish i found that the first time when the pump wouldn't pump, because it was upside down.

**Richard M.** · July 1, 2014, 07:36 AM

Re: 1956 Power Top Limit Switch Mechanicals

Well, surprising to me, I reinstalled the entire system back in the '56 yesterday......and it works.

However, I had to pull the pump assy out again as the motor rebuilder goofed up a bit! I found the problem and putting it back together.

The top worked great several times, then the motor got sluggish. I'm in the process of fixing it, but I have a question about this '56 wiring.

The diagram in the ST-12 (1955 thru 1956) on Page 12-15 shows the 2 switches for the Folding Top Limit Switches, the ones in the storage well. What's confusing is that it does not differentiate the mechanical difference between the 2, and the ST-12 only shows reference to the later micro-type switches. One is the "top frame down" switch with the long toggle lever, the other is the "top up switch" with the short toggle where the link ties to the frame. The diagram only shows #1 and #2, not which is which.

Gary, your picture is hard to see the wires below red. Both should have red at top, but one has green next, then wt. Other is red, then blue, then org.

If you have a '56 with the toggle type switches, can you tell me which wires go to which switch? It'll save me some effort to trace the circuit and all 37 steps to get to follow the sequence..

Thanks,
Rich

**Garry B.** · July 1, 2014, 07:55 AM

Re: 1956 Power Top Limit Switch Mechanicals

Rich, I have searched my entire portfolio of photos and the one I sent is the best I have. I don't have the car anymore, so I can't go look. Sorry I can't help.Garry Barnes 18531

**Richard M.** · July 1, 2014, 08:11 AM

Re: 1956 Power Top Limit Switch Mechanicals

Thanks for checking again Gary. I think I see the white at the bottom of the "long" toggle on your pic. That's the way this one is so maybe I'm good. When I get the motor back together I'll have to break out the test light and start probing.

The problem I saw is the top cover isn't moving in sequence properly, probably a misswire somewhere from the past. If I disable the cylinder from the top cover I get the top frame moving properly, but doesn't shut down.

Rich

1956 Power Top Limit Switch Mechanicals

1956 Power Top Limit Switch Mechanicals

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