I noticed that my power seat back lock on the drivers side once again quit working, when I wanted to let my little boy climb inside the car onto the backseat, and I could no longer move the seat back without unlatching it manually.
I already made 2 previous repair attempts after the solenoid for the unlatching mechanism failed, and for a while it seemed to work perfectly after the repairs were made …

The last mechanism I installed got so weak that it did no longer unlatch by itself when I opened the door…

So I had to order another used unit from my favorite source - Arizona Vintage Parts.
They sent me a perfectly working unit once again - it only had some surface rust, which I removed with rust removing gel once again (see pictures below). After this treatment it looked like new.
Like the last time, I had to disassemble parts of the back seat to replace the defective actuator with a new working one.
The new actuator I installed did work right away, but upon further investigation, I noticed that the latch did not come off as easily as it should, after it had engaged with the striker. On the passenger side the latch does not even touch the striker while it unlatches.
So the solenoid needed a lot of power to unlatch, and when the door was open for a longer period of time the solenoid got pretty hot and would eventually burn at least one of the coils inside. You can only make some minor adjustments to the mechanism itself, and there was no way to get it right on my seat so that it could clear the striker without hanging up.
This definitely already was not done correctly at the factory, and the misalignment of the striker was the reason why the drivers door side solenoid always broke. I´m sure it worked for a while when the car left the factory, but eventually it caused problems.
The only way to make it right was to slightly modify the catch latch. I just had to remove a tiny bit of metal with a file and the mechanism could then move freely, and now the solenoid only needs very little power to unlatch the seat back, once the door is opened.
I hope this is a permanent fix now…

The new part I got - before cleaning it up

Removing the rust

Removing the rust

The clean mechanism

I had to file a little bit of material from the edge of the latch, so that it could move freely. They messed up the striker alignment on the seat in the factory.

Tags:1974 Cadillac Coupe DeVille, 1974 Cadillac Repair Tip, 1974, Restoration, Seat Back Locks, Actuators

As we had an unusual warm day today with the snow melting in front of the garage, and having a couple of hours of spare time at hand, I decided to drive the Eldorados out of the garage. They both started right up as soon as the fuel pump delivered fuel to the fuel bowl. Both cars idled beautifully and it was a pleasure to see them in the bright daylight again for the first time since last October when I had put them into storage.

While I had the 67 Eldorado out I also turned on the headlights and was once again annoyed by the fact that the right one opened simultaneously, but closed slightly slower than the left one when I turned the lights off. There was a difference of around 1 second in movement between the two headlight doors.
Being a perfectionist I could not stand this, so I began searching for the problem. I already had spent some time in the past trying to fix this, but I did not succeed. The system is driven by vacuum only, so I started to look through the vacuum hoses once again. I had already exchanged a couple of them last year. I found another two brittle ones going through the firewall to the headlight switch from where a slight hissing sound was coming when the lights were on. When I touched them the hissing would become even more noticeable. I then tried to press them onto the connector of the switch and the first hose began to crumble into pieces. So I replaced all the hoses on the switch and rerouted them through firewall through the rubber insulation. There are three hoses . One is the vacuum feed (the one in the middle - I think it was yellow), one is for opening the doors (green) and one for closing (red). I also replaced the red hose behind the firewall going to a T-connector from where the vacuum is fed to the headlight door actuators. I had already replaced the two hoses after the T-connector in the past. With all new hoses in place the doors now perform almost simultaneously and quite fast. So when you run into troubles with your headlight doors, check and replace all the according vacuum hoses first. Its amazing how brittle the hoses going to the headlight switch inside the car can become over the years. It looks like they used a quite different material for these three hoses, as all other vacuum hoses are in much better shape and do not show any sign of deterioration at all.
You can see a video of the headlight doors in action below. On this video they are slightly out of sync. As it looks like they are slightly different every day, depending on temperature and engine idle...

watch on youtube or below

the vacuum diagram for the headlight doors


The vacuum diagram for the headlight doors

While the Eldorados were outside the garage my wife used the opportunity to shoot a couple of pictures she had in her mind, which she is planning to hang into the kids room. Cant wait until the medium format film is back from the photo lab. Below you can see only some digital snap shots I took.
Despite the last two unusual warm and beautiful days unfortunately winter is not over yet here in Austria, as some more snow is predicted for next week and the cars are back in the garage desperately waiting for April to come...

The Eldorado is enjoying some sun rays for the first time this year

Although she is 7 months pregnant, my wife Afra is still climbing ladders to get the best angle for her shots...

The two Eldorados in front of the garage where the snow has just melted away.

Tags:1967, Eldorado, Headlights, Actuators, Headlight doors, Video, Vacuum diagram, 1967 Cadillac Eldorado Repair Tip, Restoration, Vacuum hoses