85 GSL-SE: Rear Wiper Motor and Rear Defrost both inoperative, related?
04-17-13, 03:43 PM
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85 GSL-SE: Rear Wiper Motor and Rear Defrost both inoperative, related?
My car came from Arizona so its unlikely the original owner had any use for these parts and therefore if they stopped working left them that way. I may do the same. Before surrendering though, I want to see if these items not working are somehow related. The wiper does not move when I use the switch and I do not hear the motor. The rear defroster is hooked up but does not work either. Hatch struts appear original and untampered with. Are these two parts on a common fuse?
04-20-13, 07:39 PM
#5
The rear defroster isn't connected like the wiper
My car came from Arizona so its unlikely the original owner had any use for these parts and therefore if they stopped working left them that way. I may do the same. Before surrendering though, I want to see if these items not working are somehow related. The wiper does not move when I use the switch and I do not hear the motor. The rear defroster is hooked up but does not work either. Hatch struts appear original and untampered with. Are these two parts on a common fuse?
Does the rear defroster light come on? I have to beat on mine to get it to come on and when it does, it works fine. I've got a new switch but I'm waiting to swap out the pimp burgundy dash with a grey one once I find a good one then I'll swap the switch. Check the two connectors on the car side and see if one has a good ground, once you find that, it's the other one that supplies the 12 volts. If you turn the defroster on and the light goes on and you get voltage at the connectors, you could have a bad wire from the side terminals to the defogger element. If the light never turns on, then you could have a bad switch
The rear wiper, what a nightmare. After a while, the plastic that holds the collar on the support strut with the contacts on it weaken and when you shut the hatch, they don't connect.
First, turn on the rear wiper and check for voltage on the bottom end of the strut rod connector. If you have voltage there, it's a bad connection on the strut rod. I just used a wire tie to lock it into place and it worked. If you don't have voltage at the lower connector, I'd check the FSM first to follow the path the voltage is supposed to take and remember, you need to check that on the bottom strut connector, that the ground connector is OK as well.
In the 1984 FSM it's in section D.
I'm looking at the first page (I think) of section d and the rear wiring is pretty simple.
For the defroster, it goes from the acc or on position of the ignition switch, to a 15 amp fuse then down to the on/off switch then from there to both the indicator light and the defroster except the other end of the defroster is grounded.
The wiper/washer is almost as simple.
It goes from the acc/on of the ignition switch to a 10 amp fuse then and this is weird, the 12 volts goes to the wiper motor, then the return wire goes to the wiper switch which when turned on, grounds the wire and allows the motor to work. I guess they do this so the wiper automatically parks itself since there's what looks to be a contact to ground inside the motor so I think it powers the wiper even if you turn it off until the wiper gets to where it's supposed to be parked and the contact to ground opens up.
The rear washer circuit is on the same fuse and the 12 volts is connected to the washer fluid motor momentary switch which is the one you push in to turn on the washer and push to the right to turn on the wiper and when you push it to the right, it will stay on as long as you want it.
Follow the schematic and you should find where either the voltage or the ground stops.
Last edited by rx7lives; 04-20-13 at 07:45 PM. Reason: ETA about defogger.
04-20-13, 07:51 PM
#6
The rear defroster isn't connected like the wiper
My car came from Arizona so its unlikely the original owner had any use for these parts and therefore if they stopped working left them that way. I may do the same. Before surrendering though, I want to see if these items not working are somehow related. The wiper does not move when I use the switch and I do not hear the motor. The rear defroster is hooked up but does not work either. Hatch struts appear original and untampered with. Are these two parts on a common fuse?
Does the rear defroster light come on? I have to beat on mine to get it to come on and when it does, it works fine. I've got a new switch but I'm waiting to swap out the pimp burgundy dash with a grey one once I find a good one then I'll swap the switch.
The rear wiper, what a nightmare. After a while, the plastic that holds the collar on the support strut with the contacts on it weaken and when you shut the hatch, they don't connect.
First, turn on the rear wiper and check for voltage on the bottom end of the strut rod connector. If you have voltage there, it's a bad connection on the strut rod. I just used a wire tie to lock it into place and it worked. If you don't have voltage at the lower connector, I'd check the FSM first to follow the path the voltage is supposed to take and remember, you need to check that on the bottom strut connector, that the ground connector is OK as well.
In the 1984 FSM it's in section D.
I'm looking at the first page (I think) of section d and the rear wiring is pretty simple.
For the defroster, it goes from the acc or on position of the ignition switch, to a 15 amp fuse then down to the on/off switch then from there to both the indicator light and the defroster except the other end of the defroster is grounded.
Check the two connectors on the car side and see if one has a good ground, once you find that, it's the other one that supplies the 12 volts. If you turn the defroster on and the light goes on and you get voltage at the connectors, you could have a bad wire from the side terminals to the defogger element or an open defogger element which you can measure with a DMM. If the light never turns on, my bet is on the switch but follow the schematic.
The wiper/washer is almost as simple.
It goes from the acc/on of the ignition switch to a 10 amp fuse then and this is weird, the 12 volts goes to the wiper motor, then the return wire goes to the wiper switch which when turned on, grounds the wire and allows the motor to work. I guess they do this so the wiper automatically parks itself since there's what looks to be a contact to ground inside the motor so I think it powers the wiper even if you turn it off until the wiper gets to where it's supposed to be parked and the contact to ground opens up.
The rear washer circuit is on the same fuse and the 12 volts is connected to the washer fluid motor momentary switch which is the one you push in to turn on the washer and push to the right to turn on the wiper and when you push it to the right, it will stay on as long as you want it. Even if it's out of water, you can hear it when the engine isn't on, it's just a high pitched whine, that's good, you can eliminate that part of the schematic because part of it is working.
Follow the schematic and you should find where either the voltage or the ground stops.
Good luck, download the FSM!
