[1stGenFB]

I just started restoration on a '69 FB vert

The car has sat in my garage for 24+ years. About 10 years ago I was able to verify the power top worked.

Now I find nothing happens when pressing the switch.

Since I own a 68 vert w power top I know that car doesn't have a fuse. Is 69 any different? Any tips for where to start on troubleshooting?

Thanks

[Peter Serio]

A convertible top sitting unmoved for 10 years on a 50 year old car, it's expected that it's not going to work.

In troubleshooting anything like this you would want to break it down into sections. You have an electrical side, a large mechanical framework as well as a hydraulic side to a power top. First off check for power at the switch and ground at the pump assembly. The power wire is not fused however there is a 30 amp circuit breaker inside of the metal can which covers over the armature and magnet assemblies. Next you have the pump and 2 lift cylinders, in the top world those are often referred to as "rams." It is very common for the pump motor to leak if it sits for years. There are quite a few different sized rubber "O" rings inside of the pump motor and those will shrink over time. Next you can take loose the two 3/8" bolts that hold the top chrome plated eyelets of the rams to the folding metal framework. Just to see that the frame will unlatch off of the windshield header and lift up off of there at least a foot or 2 without binding.

Usually good repairs would involve (at a minimum) Taking the pump motor all the way apart and replacing all of the old "O" rings with new, flushing out all of the old fluid (by the year 1969 the fluid should be ATF) and replacing both top lift cylinders. Those thin flexible plastic pressure hoses get brittle from age, if those are original from when the car was new I would replace those. The pressure inside the up side of those hoses when trying to lift the top from a stacked position is in excess of 340/350 PSI. Sometimes the switch in the dash goes bad. The pump motor pulls a lot of amps and over time ( as well as use) & the switch contacts will burn or arc.

Good luck!!

[calbird68]

If it's not simply and electrical problem and you decide to pulll/rebuild the pump, this is a decent walk-thru on rebuilding the pump motor. If the 30A circuit breaker that Peter mentioned in the pump is toast, you'll need a new pump.

http://autobodystore.com/forum/showt...ly-and-rebuild

hydro-electric has rebuild kits, pumps and motors

https://www.hydroe.com/product-resul...iac%20Firebird

[1stGenFB]

Thanks both for the comprehenive information. no time yet to tear into it. It seems most likely an issue with the switch or a loose ground. If it ends up being the motor I will just replace it. that thread showing the rebuild looks pretty scary hahaaa.

[calbird68]

So a couple of things, following up on what Peter said.

First step is testing electrical. The pump will generally turn over if it gets power. From there, there's a variety of things to check before buying a new motor (which may not solve the problem). I can at least walk you through my experiences once you get past that point

[north]

A good sequence to test...

power to the switch?

Power out of the switch (when activated)?

Power into the motor unit?

motor operating?

fluid level-leaks in the system (reservoir, lines and cylinders)?

unbolt cylinders from top and test system without load?

check top frame for binding?

My experience is assuming that a line or cylinder isn't visually failed the problem is 95% of the time the switch. This system doesn't use a relay so full amperage flows through the switch. (run a good running system through a cycle or two and feel the heat in the switch.)

[1stGenFB]

I removed the switch from the dash. I was surprised to learn the black wire is hot. using the switch did not test positive at the other end connector from the harness.

After splitting the switch apart I was able to jump the black wire to red then black to green. Each time I get a positive test on the other end. This leads me to belive the pump is bad.

Still to do is to check the convertible top frame will move when physically pushing it. currently it is in the down position.

Seems like the pump is suspect. Maybe I will give that pump rebuild thread a more serious look.

Thanks