Hello everyone. I am looking to tackle fixing my convertible top over the coming week. I bought the car with the top not working because the hydraulic line on the passenger side cylinder was busted and leaked all the fluid out. I replaced the lines and added trans fluid to the convertible top motor. Once I got enough fluid added and cycling around the top started working going up and going down. Although it was working in reverse meaning when I pressed the switch up the top went down and vice versa. Almost like somebody else wired the switch wrong to begin with.

Anyways after cycling the top up and down a few times I cannot get the top to go up. No sound from the motor. It still works with bringing the top down. I placed my multimeter on the terminal leads coming from the switch and as suspected I got 12V on one terminal but nothing on the other.

So my question is if anyone had any tips at removing the switch without having to remove the dash? I've read you have to remove the radio to get at it. I have also read to remove the glove box to get at it. Hoping to get any sort of insight what I am up against and possibly save a lot of 4 letter words from exiting my mouth.

Thanks all.

 

You might be able to get at the switch through the glove box opening if you remove the glove box. The pics below show the switch location on my '67. Should be the same on a '66. I believe the factory screws are 1/4 hex-head screws. Mine has been mutilated in some creative ways and the screws have been replaced with phillips head screws. My switch is also installed or connected backwards.

 

Thank you for the images cjsdad those really helped. I just got the switch out and you were correct (2) small 1/4" hex head screws hold it in. It was not too difficult getting at it once I got the glove box insert completely out. After pulling off the 3 wires I fumbled around with a small 1/4" ratchet until I realized a small nut driver was the proper tool for the job. That got the bottom screw off quick and the top one loosened. Since the nut driver was a little too long to get the top screw completely out I then used just the socket and it came right off.

I have a new switch on order hopefully putting it in will be as easy as taking it out. I'll have to use a trick I learned years ago when I was a jet engine mechanic in the Air Force to put some Vaseline in the socket to hold the screw so it does not keep dropping out when trying to get it started.

 

If the top motor is not making noise, there’s no electrical power getting to it. Or it’s burned out. I have ‘66 big cars. Not Cutlass/442’s. On the big cars, Olds ran the power top feed through a 40 amp circuit breaker on the firewall. It looks like a “T” with a screw post on either edge of the “T”.

I don’t know if they did the same on the A bodies, but it’s worth knowing.

The switch is pretty simple, it just feeds electricity either to the the Up or Down side of the hydraulic pump. What you’re looking for is whether there’s a component between the battery and top switch stopping current flow to the switch. In a pinch you could even run a temporary (heavy gauge) wire from the battery to the switch to confirm where a problem might be.

Hope that helps.
Chris

 

OP says the switch works in one direction but not the other. That is why he is replacing it.

Your wiring should have a 3-wire connector that plugs onto the switch to keep them in the right position so if yours is working backwards, you may be able to turn the switch over. I don't remember if it will fit both ways or not. If not, you will need to reverse the wiring somewhere.

BTW, my brother was an aircraft electronics repairman in the Air Force.

Here is a pic of the relay on the firewall if you want to inspect it.

 

Yes I did have 3 wires all with quick disconnect ends on them. I had enough length on the wires to pull them a bit into the open cavity of the glove box area so connecting the new switch should be easy. That also gives me the opportunity to make sure the up and down wires are on the correct terminal. With the switch in my hand it looks like one of the mounting brackets is slightly longer than the other so while I thought you can simply flip the switch around I'm no longer so sure.

With the switch out I did do a continuity test with my multimeter. I got continuity on one of the posts that go to the motor but not the other so that jives with the top only working in one direction.

 

I cannot confirm this, but have heard that the replacement switches are not the best quality so it may be a good idea to keep the original so you can clean and restore it if needed.

 

This is what the connector on the switch should look like. This one is obviously dirty, but you get the idea.

 

Thank you for uploading the image of your wiring harness. Here is what I have on mine. Appears at some point somebody replaced the end receptacle piece you have with the terminal end clips. I got the new switch in and was able to swap the wires around to get the top working so pressing up is up and down is down. Getting it back in was a slight PIA reaching my right hand back through the glove box insert cavity but all is back together and working well now.

 

Glad the top switch is fixed!

Just so you know, GM in those years used a system called Packard 56 for its electrical terminals and their plastic shells. Many of these are still available.

I think I generally get mine from clips & fasteners.com, but dig around the web and you may be able to find the correct plastic shell. You can easily find the male and female connector spades in quantity for not much $$.

If the previous owner changed out this connector, it likely there are other modifications / hacks you might want to repair.

Cheers
cf

 

So glad you were able to get the top working.

Like Cfair said though, the crimps on those connectors look a bit sketchy so you might look into putting the correct connectors on with the correct crimpers.

I understand that it is working, so don't stress on it. But if you run out of projects, you might revisit this one. 👍

 

I'm not going say I disagree w/ you, I have no direct knowledge of a 1966 Cutlass convertible but that looks like a circuit breaker - not a relay. One of the issues w/ convertible switches becoming faulty w/in this time frame at least, is the fact they used no circuit relay and instead pumped a ton of current directly through the convertible top switch - yielding/rendering these switches to fail. Many (including myself - 1971 CS convertible) have instead installed a proper circuit relay into the convertible top switch wiring. Installation of a circuit relay into the convertible top wiring is a better method of wiring. Something to consider.

 

It is a circuit breaker. Thanks for being the ever-present sexual intellectual.

 

 

To be completely honest when I raised and lowered the top after installing the switch I would only hold the button down a few seconds at a time and then wait like another 30 seconds before repeating the process. Too afraid of blowing out another switch. I've been doing some reading on this topic of adding relays as it does seem like these switches burn out easily and for such a small part they are not cheap. I paid like $85 for the damn switch and waited a little over a week to get it. I'm not an electrical engineer but looking at the diagram it appears mounting the relays in the back by the pump would be the most straightforward approach. I could use the same ground as the pump and have the up/down wires coming from the switch and from the motor. I would just need to run a 12V wire coming off a 40Amp in the fuse box and split it to each relay. Do I have that correct?

 

I believe you have it. I've been evaluating how well Google AI provides instructions, directions, addresses searches, etc. Sometimes the results are blah, sometimes fair, sometimes excellent, etc. Thought I'd challenge Google AI w/ installation of a vehicle power relay. I was delightfully surprised w/ the results:

To install a relay switch for power in a car, you need to connect the relay's power source (terminal 30) to a constant 12V battery wire, then wire the trigger wire (terminal 85) to your switch, connect the ground wire (terminal 86) to a chassis ground, and finally, run the power to your accessory (load) from the relay's output terminal (terminal 87), ensuring you use the correct gauge wire for the current draw of your accessory.

I'd add ensure you have the properly sized relay & properly sized wires.

Similarly....

Identify the power source:
Find a suitable power source from the battery, usually a thick red wire, and connect it to the relay's terminal 30 (power input).
Connect the trigger wire:
Run a wire from your switch to the relay's terminal 85 (coil power).
Ground the relay:
Connect a wire from the relay's terminal 86 (coil ground) to a solid chassis ground.
Wire the load:
Connect the power wire for your accessory to the relay's terminal 87 (output).

 

You won't find a 40 amp source through the fuse panel so the easiest thing to do is use the power and feed wires you already have. The easiest way I have found to wire up relays is to get pre-wired sockets for them. Make sure you get what you need for your relays as well. The pics below show the difference between 30 amp and 60 amp, fused and non-fused, 4 connector and 5 connector relays. Also the difference in wiring size for the heavy vs. light duty relays. You should use 4 connector, non-fused, 60 amp relays, but the 5 connector is easier to find. Linked below. The "normally off with ground trigger" wiring is the easiest for this application as well. Use the dash switch to trigger the relays with ground. The sockets can be linked together for ease of mounting.








irhapsody 80/60Amp 12v 5-pin Relay Kit, spdt 12-Volt Automotive Relay with Heavy-Duty Pigtail, 6-Pack https://a.co/d/eikVLid

 

cj very nice write-up