1950s Hydro-lectric window help

[CadillacFlashback]

52 Fleetwood rear windows do not work from rear switches.  All four work from driver door, passenger works from passenger door.

Voltage is making it to the switches.

If I remove the motor and cylinder wires from the switches, the switch will distribute voltage to the action studs properly when activated, so they seem to be good.

But when the motor and cylinder wires are attached to the switch, no voltage distribution to the action studs shown on multimeter and no window action or noises.

Tried a brand new switch as well, no change.

Any ideas?

Thanks

[V63]

I guess I would verify that the 3 wires on the switch are in there correct positions? The fabric color  codes fade off. Also verify there are no bare spots to contact bare metal structure upon assembly. 🤷🏽�♂️

[tluke]

When you activate the rear window (or any window) switch it sends electrical current to two places. First to the hydraulic pump in the front of the car which then pumps hydraulic fluid to all windows/seat/convertible top that will be used for lifting. It then also sends current to the specific cylinder (in the door) for the window you are opening which then opens the valve and the window goes up. The same for going down except the fluid simply drains through the return tube and a spring helps lower the window.

So if the switch is working and you push the toggle to raise the window, current flows to both places. If the wiring from that switch to the main pump up front is good, not broken somewhere, but the wiring to that specific door cylinder is bad, you'll measure current flowing (to the pump) but nothing happens. You might be able to hear a click or something when the main pump turns on if you have someone up front listening. Likewise, if the wiring to the door cylinder is good but a broken connection to the main pump, the valve in the specific door cylinder will open, drawing current through the switch but the pump won't activate and again nothing happens. Since neither switch in the back will move the windows, there's a slight better chance the broken wire is to the main pump but since the car is 74 years old, it could be that the wires to the door cylinders on both sides is bad. Also since the front window switches are all fine, it's also more likely the problem is the pump wiring in the back portion of the car, like where the two wires from the two rear switches are spliced together before turning forward. I don't have a wiring diagram but I would guess you'd be looking under the rear driver side door sill plate for that wiring. 

If you show no current on either switch then both the wires from the switch to the pump and to each separate door cylinder valve is broken. I guess with a 74 yr old car that is also possible.  When you check the current without the wires attached you're grounding your multimeter lead some place on the car manually. When you test after attaching the wires where are you grounding the multimeter?  Even if one of the wires was broken and grounding to the car, you should get a reading on the multimeter - unless the circuit breaker trips which would stop all the current until it resets but then you should see a momentary reading and then nothing and later after reset another momentary reading.

You mention removing the motor and cylinder wires from the switch. I thought that the center post is a positive feed which should always have power (with ignition on??) and the other two posts were for up and down, up using the main pump up front and down just opening the relief cylinder valve in the door  to allow the fluid to escape. 

Good luck

[CadillacFlashback]

Tluke—lots of info there, thanks.

To recap my situation:
Have power to switches
Switches test as working
I get no action or noises from rear switches up/down
Rear windows work from driver switch

Additional info I didnt include in first post-seat also not working.

All four window cylinders were replaced by the previous owner.  He says that the rear switches (and seat) all worked until shortly before I bought it.  I tend to believe him.

I plan to see if I can trace wires to look for break/short but was not sure where they run.  If it is under driver's sill plate that is a huge help, I will see what I can find.

Any other help anyone can offer will be great.

Thx

[tluke]

So the fact that the seat doesn't work narrows down the issue a bit. It's unlikely that the wiring connection from the all three switches to the cylinders on each of the rear windows and the seat all went bad so my guess the wire from the switches to turn the pump on up front is the culprit. The two rear window switches likely are spliced into each other under to driver side doorsill plate near the B pillar and then the seat splices into the pump wire at the same location or maybe slightly more forward. The front window switches probably splice in behind the kick panels or under the dash so they would still connect to the pump. A wiring diagram would help confirm the location of the splices but more importantly give you the color of the wire you're looking for. You might look at the pump under the hood and see what color wire is connected to the solenoid/relay and that should be the color your looking for under the door sill.

I still don't understand how pushing the rear switches doesn't at least click the solenoid/relay in the door (or under the seat) unless they won't trigger unless the pump is on and providing pressure. I don't know how that would work.
Terry

[CadillacFlashback]

Revisiting this...

Finally had time today to try again on this problem.  I discovered that the wires come through passenger firewall behind glove box, Y-off going left to driver door, right towards passenger kick panel, then another Y heading to passenger door/rearward under passenger footwell carpet, then in front of the seat it turns towards the driver and Ys again with one side continuing across the floorboard toward driver and the other curling back under the seat and eventually into passenger b-piller/rear door, the run across the floor in front of the seat the Ys on driver side to go to seat switch/to driver b-piller/rear door.  So at least I found all that.

There is nothing obviously wrong looking with any of it.  It all appears original and undisturbed, the cloth loom is all in tact, nothing oddly worn, etc.  Doesnt look like any one has seen what I saw in 72 years. So after 4.5 hours invested today Im still exactly where I was...all four windows work from driver door, passenger window from passenger door, but rear window switches and seat do nothing despite power at the switches. Man is this frustrating.

[tluke]

Scott,
Scott, you've made a lot of progress! It's not wasted time! You now know where to test with your multimeter. After re-reading your first post I was little confused about your switch testing so even though I still think the issue is in the wiring, take a look at your switches again. Help me understand how you're testing power at the studs and that your wiring is connected correctly. The only things common to all three non-functioning switches are the lines connecting to the BAT stud have a single shared circuit breaker and then all the lines that connect the UP/MOT stud back to the motor/pump. Take a look at the included wiring diagram and then try this:

   1. Verify a switch works (disconnected from all car wiring)
      a. Multimeter continuity test from center stud to both outer studs one at a time  (Also the other two switches should be disconnected from power during testing of each switch - tape up the ends of the not-being-tested BAT/power wires to prevent shorting)
      b. With switch pushed up it should test positive for continuity with one lead on the BAT stud to the other lead to each of the studs  -MOT & CYL, that's because pushing up needs to energize both the motor/pump on the firewall and the cylinder valve in the door in order for the window to go up.
      c. Switch down should show continuity just from BAT to CYL stud, i.e. confirm there is NO continuity from BAT to MOT when switch is pushed to down
      d. If your outer studs are not labeled in the back of the switch as MOT and CYL, remember MOT is the stud with continuity only when switch is up and CYL is the stud that has continuity with the switch in either up or down positions - remember which is which as you connect the wires. (Gray tracer with Tan to MOT, Black something or other to CYL)
   2. Verify switch is correctly connected to wires
      a. Connect RXT (red tracers on tan) wire to center BATtery stud - test for power from BAT stud to ground on car (should provide power with ignition turned off but just to be sure switch ignition to on)
         i. Test from BAT stud to ground on car should show 6V when pushing switch up
      b. Connect GXT (gray tracers on tan) wire to UP/MOT stud as confirmed in continuity test - test for power from MOT stud to ground on car with switch pushed UP towards MOT stud
         i. If no power in MOT stud, test again from BAT stud to ground on car
         ii. If no longer power now at the BAT stud check for circuit breaker being tripped
            1) If circuit breaker is tripped when the MOT stud is connected it points to that wiring as the issue - check the "Y" splices for corrosion or shorts on the 16GXT (gray on tan) wiring as discussed below.
            2) If there's no power at MOT stud but circuit breaker is not tripped the problem becomes ambiguous. Remember, circuit breakers trip automatically then recover automatically and if the problem is still there will trip again and again. Letting the rear door switch spring back to the center likely removes the power to the potentially bad wiring so by the time you try the front switch it has likely recovered. It is better have someone watching the circuit breaker (on the firewall I think) while your connecting and testing the rear window switch.
            3) Test for  power from Down/CYL stud through multimeter to ground with GXT wire still connected and pushing switch up. (remember, up also needs to energize the cylinder valve for the window to go up)
            4) Disconnect the GXT wire from the UP/MOT stud before the next step (Leave the BAT stud connected)
      c. Connect the Black & ?? wire to DOWN/CYL stud with the MOT stud disconnected to better isolate problems. Run through the same tests as described above for the MOT stud. This test being done without the MOT wire connected will likely pass since it works from dedicated wiring from the switch to the cylinder while the MOT connection uses wiring shared by every other switch in the car.
      d. Disconnect all wires and repeat for the other two switches.
      

So if your tests show a potential wiring problem that problem is most likely in one of the "Y'"splices.  Even though they look fine, that's the place where corrosion starts, where two separate wires connect to each other, especially when that Y is on the floorboard under carpet which gets wet and holds the moisture for long periods of time over 72 years. You need to open up the Ys and inspect them. Here's how to know where to start:
See the wiring diagram included that shows the wiring for the hydro-lectric system (just an electrical path not a physical representation). Ignore the wires to the Top Control Switch and Top Valve as they are for convertibles.  The gray line is the wiring from the two rear windows and the seat adjuster switches (3 total) that provides power to the Motor/Pump (labeled 16GXT).  The yellow numbers are the Y's that you identified but just the ones that are between the pump and the 3 non-functioning switches (rear doors and seat). 
#3 Represents when you described : "then in front of the seat it turns towards the driver and Ys again with one side continuing across the floorboard toward driver and the other curling back under the seat and eventually into passenger b-piller/rear door,"
#1 & #2 are likely good since they come from the master switch and the passenger switch which still work. #2 could be partially bad so the front passenger switch works but nothing behind it.
*** #3 feeds all three switches not working and is likely the culprit.*** 
#4 just feeds the seat adjuster and rear driver-side switch so while it could also be bad wouldn't affect the passenger switch.

You're going to have to open up the wiring splices to test it. You're going to need to touch the positive lead on you multimeter to a bare spot on the wire in front of #3 Y, but before #2, find some place on the car to connect the ground from the meter then push the rear passenger door switch up to apply power. You should see six volts. If not you're going to have to open up that Y and clean it up.

Make sure you're testing the correct wire. The "G" in GXT wire stands for gray tracers over tan. The red RXT line (RXT -red over tan) is likely in the same wiring bundle but will likely be good since you say you have power to the switches. As you can see in the diagram there are also a couple of "B" (black &?) wires that go back to the front main switch panel that could also be in the bundle, but they have no splices (except inside the door).  Telling black from gray on 72 yr old wires might be tricky. The color you are testing is the one on the UP post on the switch (MOT  for motor/pump in the diagram)
Click to enlarge

[CadillacFlashback]

Tluke great info-thanks.  Ive tested the switches in a similar fashion as you describe but will try again following your instructions closely.I also need to go into the doors.  The wires connected to the switches are not factory, so there's splices in there that may be the culprit