The 1965 Buick Skylark GS Convertible that I recently acquired has been an amazing vehicle to drive and learn about. This car has been restored at some point back in the 90s while it was still living in California. It is triple black in color with a 401 Nailhead V8 and a three speed transmission. This car is not numbers matching, it has the motor and transmission out of a 1966 Buick. The car would have originally come with a 2-speed transmission, and I must say that having that extra gear makes the driving experience much nicer. 

My history with this car starts around 2008. When I first saw this car it was up on a 2-post lift in a barn with a gentleman chipping out mud from underneath it because it had just come back from a road rally in Thailand. My immediate reaction was ‘that is a really nice car! I can't believe that it was just overseas doing a rally’. The next time that I saw that car up close was last summer, 2024. It was sitting in the corner of the same barn and it had a layer of dust on it. It clearly had not moved in quite some time and it looked sad sitting there with the top down, and dust mites aplenty.

The owner had commissioned me to get the car out and get it running again as he wanted to sell it. I had trouble getting it running, and a lot of the electronics on the car did not work. The electric-over-hydraulic convertible top did not work, and it was clear as I dug further into this car that it needed some love. 

I got the car running after tinkering with the carburetor, and I backed it out close enough to an air compressor so I could pump up the tires. I gave the whole car a quick once over, checked the fluids, and then drove it to my home which was about 30 minutes away. It surprised the heck out of me because it actually ran extremely well for that drive. However, it was immediately clear it needed work on the brakes, transmission, and carburetor, and there were definitely electrical gremlins. 

As I got the car into my shop and started looking into its issues, it quickly became apparent that it had had multiple people work on it over the years. This is not uncommon with these older vehicles, as most people just need enough done to keep them running. A lot of what had been done was not factory. One thing you'll learn about me pretty quickly is I really appreciate vehicles (especially of a classic era) that retain their factory systems and work as intended with their factory set up. That's not to say that I don't see the importance or the benefit of having modern things on older cars. For example, HEI distributors or beefier sway bars or better brakes and things I consider ‘bolt on modifications’. But at the end of the day, I like it when a classic car has the correct style systems in place and they work correctly. 

Obviously, this is foreshadowing as there were a lot of things that I did to this Buick to turn it back to stock and to get as many of the factory systems working again. 

One of the first things I made sure address were the brakes. The master cylinder was leaking pretty badly at the seal where the piston rod goes through master cylinder. This car had been upgraded to front disc brakes with a dual master cylinder, which means they are power brakes with the booster. This car originally came with four wheel drum brakes, and it would have been a single reservoir master cylinder. I assume it came with power brakes, but I don't actually know. I went to replace the master cylinder and when I took it off I saw that it had been leaking for quite some time. With brake fluid being extremely corrosive, it had eaten away the inside diaphragm on the booster. I knew it had a vacuum leak, and this was a good place to start. I replaced the booster and I put on a new dual cylinder master cylinder and bled the brakes. They worked beautifully….at first. More on that later. 

The next biggest thing that I worked on was the electrical system. While I don’t love electrical work, I am decent at it. Maybe it’s because I’m so picky, but I want it done a certain way and I want it done right. Instead of splicing to send power where it is missing, I want to understand why something is shorting out and find the cause. This Buick was an excellent lesson in patience when it comes to troubleshooting electrical issues. Under the hood and under the dash the wiring was a massive undertaking to get the car back to where I wanted it. For a little more detail, most of the cars from the 60s and 70s did not have actual gauges for oil pressure, temperature, voltage, or really any other gauges to see the vitals of the car and how it’s running.  They have what are called ‘dummy lights’ so if an issue arises, it lights up the dash with an indicator telling you that something is wrong. This Buick has these dummy lights but it also has aftermarket gauges for oil pressure, temperature, and voltage for the charging system, something I am totally on board with. I recommend any classic car owner with dummy lights install these aftermarket gauges.

The place that I went into an electrical tizzy was my desire to have all of the original dummy lights on the dash work in unison with the aftermarket gauges. To do that I took the entire dash apart in this Buick and found quite a few wires that had been either added, cut, weren't correct, went nowhere, or even some live wires that were shorting out to ground. You name it, I found it. Picture this: I took the driver's seat out so I could lay on the floor of the car with my feet up on the back seat with my head under the dash so I could see exactly what was going on. I spent about a week cleaning up the wiring underneath it and fixing everything. They do make a replacement dash wiring harness for these cars but it's quite pricey. I made the decision to keep the original harness once I cleaned up the majority of the dash wiring, sans a couple lengths of wire that I ended up splicing and soldering together which I think is the best connection. It's been fine ever since.

After that, I tackled the gauge cluster. The first issue was that the printed circuit board on the back was in rough shape. It had some of the brass connections separating from the board so I ordered a new one that is reproduced to OE specifications. I replaced all the bulbs with LED bulbs, I lubed the speedometer, and made sure all of the dummy lights worked before I buttoned it back up. 

The next challenge was to make sure the dummy lights were connected to their correct locations. To preface this next part, I ended up replacing the entire engine wiring harness with a remanufactured one that is correct for the car and came in the factory color-coded wire colors. It was awesome and a huge time-save to just plug and play! All the correct terminals were there, and I specified it with the HEI ignition wire for a direct 12 Volt ignition source to the MSD ready-to-run distributor.

The oil pressure light sensor was disconnected, and its connector was just dangling down next to the transmission bell housing. The port where that was supposed to be connected was taken by the mechanical aftermarket gauge. So, I put in a brass tee and put in the dummy light sensor, then the hose that goes to the oil pressure gauge, and that way I had both of them hooked up. Next was the coolant light sensor. On the 401 nailhead, this motor actually has two separate plugs for coolant passages, one on the front of the motor, another at the back. I put the correct sensor into the front plug area, and removed the aftermarket gauge sensor that was there. I then put the aftermarket sensor into the rear port, and voila! Dummy light and gauge working!

Stay tuned for Part 2, where Brendan continues the process of rehabilitating this old Buick. Motor on!