Power windows electrical problem

[85 Cab 81 SC]

Hopefully an electrical guru can save me from needlessly pulling my door panels. Situation: all window switches went inoperable at the same time; fuses and wire connections at the fuse panel check-out good; 12volts to relay pin #86 only; even with pin pulled out just far enough to reach the pins with a probe only pin #86 has voltage; there is no voltage to any of the wires/connectors at the door mounted switches (door opened or closed has no effect); I have changed out the relay but that has made no difference; all the wires going to ground at the bolt near the fuse panel show zero resistance to the negative side of the battery. I suspect my problem is located inside the front compartment but I need guidance as to what I should be checking and its location. The vehical is an '85 Carrera Cabriolet (no power to the top).

Any suggestions anyone?
Ron

[nhromyak]

I don't know if you have noticed, but with the key in and in the "accessory" position, the power windows work.

I can pull the key and as long as the doors have been closed since the key was pulled, the windows still work.

Key out and open the doors, and the windows will no longer work UNLESS the key is moved back into the accessory position (or beyond).

I am not sure what controls this though.... I presume there is relay of some sort for the key/door/ window.


Could also be a bad drivers side window switch. I found this MAY affect your passenger switches from getting power.

Good luck.

[rfix'n]

Ron,

If I read the wire diagrams correctly then you should always have power to pin 30 of the relay. You should have power to pin 86 only when the key is on (accessory). You should also have power at pin 87 when the key is on. 85 should always be ground. If you get no reading at pin 30 I'd start there and trace backwards.

[steve911]

Ron--
I had a similar occurence about a year ago in my '85. Try replacing the fuse with another one (humor me). Mine looked fine - I put in a new fuse and now the windows work fine. Then make sure all the electrical connections are nice and shiny.

[targa80]

Nick Hromyak:

The relay has several transistors/diodes/resistors installed that connect to the door switches at terminal 85b and would effect the operation of the relay depending if the door is open providing a ground to terminal 85b..

[85 Cab 81 SC]

Wanted to thank everyone who responded to my questions. I was hoping to announce a happy ending; not yet unfortunately. When all else had failed I was down to peeling back the wire harness to the relay and lo, the wire colors matched a tempostat relay not a power window relay. OK, someone mixed the order of the relays; I can deal with that. My attitude changed when I failed to get a continuity reading from any of the relays.
Replacing the hot and ground wires with jumper wires at the driver's door switch got the driver's window working fine (ran out of time to reconnect the switch for the passenger's window).
I should add here that in trying to locate the missing power window relay I failed to get a continuity reading from the window switch to any fuse even checking both terminal sides of the fuse holders. I do, incidentally, disconnect the battery and even use in-line fuses on my jumper wires.
My next step is to remove the door panel and work from that direction vs trying to trace thru the maze of wires and harnesses under the fuel line and filler tube. It also gets me started on getting to the power mirror that hasn't worked since I bought the car.
Now for some brain teaser (at least to me) questions: Why does the power window only work when the key is on even when I am jumping the power and ground leads at the door switch straight from the battery? Could whoever cobbled the wiring have simply eliminated the power window relay and just brought a hot lead to the door switch? Does the door switch only control a relay built into the motor and that relay changes the polarity from a seperate power source? That would answer my first question. Glad I enjoy working on the car and its certainely a learning experience.

[targa80]

Ron:

If the window relay was removed and you were to jumper a wire from the + battery terminal to 5 of either switch on the drivers door with all of the wires still attached to the door switches I believe the windows should work on both sides. Unless the switches are wired wrong. Terminals 5 and 3 on the drivers side switches should be a color RT/BL Sorry I don't have the color call out chart with me. I only have a copy of the schematic page with the window circuit. The same RT/BL wire will be connected to one side of fuse 1 in the trunk. The other side of fuse 1 should be a color SW.

As a side note the schematics for my 80 SC and the layout of the fuse number system was reversed in other words what is fuse 1 in the schematic and what is indicated in my car is actually fuse 21. I.E fuse 2 is 20, fuse 3 is 19. Since I have gutted my car I had to be sure of the fuse wiring for reassembly. Once I figured that out the wire colors matched the color code call out in the schmatic. Just something you should look at if fuse 1 does not have the correct color wire as called out in the schematic.


Why the jumpered wire will not allow the windows to open with out the key in the ignition is not apparently clear to me. I can see how you need the key switch on with the correct circuitry with the relay in place.

[targa80]

Just came home and I looked up the color codes for the 1985 schematic

SW = Black
WS = White
RT = Red
GN = Green
GE = Yellow
GR = Gray
BR = Brown
Bl = Blue
LI = Violet