Lukewarm

The top has quit working on my 71 Cutlass Supreme Convertible. The switch never returned to center (off) on its own, so I'm thinking the pump motor may have burned out.
Is there a fuse, relay or fusible link I need to be aware of?
Any trick to getting the switch out of the dash?
I'm assuming I'll have to drop the A/C ducting to get a look behind the dash at how it is mounted.
I've added fluid to the pump reservoir in the past, so I know how to access that.
Can the motor be tested before removal by simply jumpering to a battery and reversing the leads for the two directions?
Any tips on removing the motor without making a huge mess with the fluid?
How about operating my top while waiting for the new motor to arrive and time to install. Can the top be operated manually or does that just get more air in the system and create more problems?

And finally any experience good or bad with vendors that you would reccommend or avoid when looking for quality parts?

As always, thanks for any info and advice.

allyolds68

On 68's there's a heat breaker on the firewall near the master cylinder but the 68 switch sucks and would likely would burn out before the breaker opened

72blue442

The relay should be on the fuse block, near the park brake pedal. The switch is mounted with 2 screws into the panel. I accessed mine by removing the left instrument cluster and going in from the front. The switch is the weakest part of the circuit, they burn out real easy.

MDchanic

That would probably indicate that it's no good.


Maybe, or maybe the switch is just messed up.


Yes, as stated, should be on the firewall under or behind the brake booster.


Yes. One wire is powered for Up, the other for Down. Ground is through the motor.




Yes, just unbolt the hydraulic cylinders from the top mechanism and lay them out of the way.
The top will be a bit heavy.

- Eric

Lukewarm

I managed to get the switch removed from the dash through the left instrument (fuel gauge) opening. The connector must be removed first to access the one screw. I took some pictures I will have to post in the future. Maybe that will help someone who attempts this in the future. Still 12 volts to the switch. Even when the switch is bypassed, the motor doesn't make the slightest sound when jumpered directly. I'll give the local motor repair shop a try before ordering the top pump. Switch is on order.

Thanks again for all the info.

pmathews

I replaced the brushes in my convertible top motor, and it saved me the cost of buying a new pump/motor (about $200). The brushes only cost $8, but I had a really difficult time finding them. I ended up buying some off eBay, and it's been working great ever since. Replacing the brushes is really easy, would only take an hour if you have the brushes and know how to use a soldering iron. Good luck!

69 Ragtop

This means there are three possible problems:
1) Bad breaker (most likely).
2) Motor problem (possible, but unlikely).
3) Wiring problem (unlikely).

I would make a small jumper to put in place of the breaker, then temporarily jump across the switch again.

(Thanks for letting me get some use out of this electrical engineering degree... )

Hurst/Olds 73/74

Lukewarm,
Can you still post some pics of how you took your switch out of the dash? I also have a '71 Cutlass Supreme convertible and I think my switch is bad. The switch has always been a bit fussy since I got the car a couple of years ago, but suddenly, the top will not go down. It still gets power to go up, but no motor noise at all for going down. As you know, it's hard to see up under the dash, so any instructions and photos would be great! -Steve

Lukewarm

Thanks for the nudge H/O. I don't frequent the site often in the summer months.

To recap, the switch on my recently re-aquired 1971 Olds Cutlass Supreme convertible was still functional to put the top up and down but it didn't self-center any more. If you didn't return the switch to the center position after moving the top, the motor would keep running. This is what apparently happened the last time I drove it home from work. The next time I wanted to put the top up, no dice. Pulled the back seat and jumpered directly to the motor and nothing. I have dissassembled the motor and one of the windings has seperated from the armature, probably due to overheating. The local motor shop wanted more to repair it than a new one. I will probably attempt to resolder it myself sometime but have ordered a new motor.

Now for the switch replacement. I attempted to access if from the bottom but quickly realized that is next to impossible. I removed the bezel around the gauges and then removed the left gauge cluster. It is still next to impossible to see and access the two hex head mounting screws but this is as good as it gets. I was able to use a small mirror to view the back of the switch. Let me know if you have any specific questions or need clarification of any photos.

IMG_20140615_143924_zps8fa356b5.jpg

I was unable to remove both screws until I unplugged the harness. The wires block direct access to the one screw. The harness is clipped into the bracket that holds the switch to the dash. I took these pictures showing the switch (only partially plugged in) the mounting plate and the harness plug.

IMG_20140615_150511_zpsf015d037.jpg

IMG_20140615_150702_zps5e4db768.jpg

IMG_20140615_150808_zps075a1487.jpg

Hurst/Olds 73/74

Awesome!!! Thank You, Thank You, Thank You!!! A little understanding goes a long ways towards not prying and breaking plastic things! I'm going to attempt it in the morning. Thanks again for taking the time to post pics for the rest of us!

Hurst/Olds 73/74

Lukewarm, I followed your instructions and it worked great! I also took a few photos of the surgery to share with others attempting it in the future. I was able to repair my switch and saved myself about $70 or more. The top goes up and down great and the switch movement is tighter and crisper than it's been since I've owned the car! For those in the future who need help, I'll add to what Lukewarm already said:

1. Remove the dash gauge bezel
2. Remove the gas gauge
3. Insert your wife's hand-held bathroom mirror under the dash so you can see the back of the convertible top switch through the hole where the gas gauge was.
4. If you haven't already, disconnect the battery.
5. Gently pry the black wire connector off of the back of the convertible top switch.
6. Using a 1/4" ratchet and 1/4" socket, remove the two screws that hold the convertible top switch.
7. The convertible top switch is held together with two spring clips. Remove the spring clips and you can tear down the convertible top switch. After 40+ years of service, the spring-loaded plastic plunger on my switch had deteriorated (melted on the end), leaving a few small pieces of plastic to float around in the switch. One of those plastic pieces became lodged between the contacts, causing the switch to malfunction. I cleaned out the switch, bent the trigger to it's optimum performance (bowed upwards on the ends slightly so both ends cannot ever make contact at the same time with the contacts, but not bowed enough that the contacts can't meet when the switch is thrown up or down).
8. Connect the battery, temporarily plug in the switch, and text your repaired switch before installing the switch in the dash.
9. Repeat process in reverse to install the repaired switch.

35tac

Anyone have anything to add to this relative to a 66 vert?
Thanks
Wayne

pmathews

The wiring in the 66/67 switches are problematic since the contacts are too small. The amps pulled by the motor can roast the tiny switch contacts over time. I installed relays to solve my switch problems. With a relay, the switch can control the high amps without seeing the full amperage across the tiny contacts. Fixed this two years ago, and it has been working flawlessly since then.

35tac

Thanks, can you provide any details.
Thanks
Wayne