Heated rear Screen

jp928

Active Member
#1
My car has a heated rear screen fitted, but does not have a switch for it. I dont know when the heated screen was fitted. There is a new switch provided. Is it likely that the wiring for the screen is in the loom ? There appear to be leads coming off fuse 4, of the correct colour (SN) but I dont see wiring for the switch so far. More digging needed?
I hope everybody knows heated rear screens were a Rover innovation? Originally fine wires embedded in the glass.
 

Tom W

Active Member
#3
Jags of the same period have rear screens with the same fine wires inside. They look like the heated front screens you get now.
 

arthuy

Well-Known Member
#4
My P5b has the original rear screen.

There is just a silver strip at the bottom then the fine wires running through very classy and effective.

What year is your car? later cars have an unlabelled switch at the drivers glove box. Little red neon rocker switch.

If you don't have the switch surely the wires will be in the with the hazard relays. As the come off the same wiring loom branch.
 

jp928

Active Member
#5
Car is a 74 series 2 . The hole is in the metal part, but the vinyl trim has not been cut. The PO has provided a switch (Pull type with tell tale light).
 

roverp480

Active Member
#6
My 2200 parts book lists both a push pull with tell tale built in and a bezel stating heated screen and alternatively a rocker with internal light , the rocker I understand being the later fitment. If there is a round hole in the panel, its the push pull switch.
 
#7
My car is a late 72 3500 auto and I have found that the wiring diagram 86.00.01 Sheet 2 in the Rover workshop manual suits my car. It shows the wiring for the heated rear window, switch and relay. The items to look at are 71, 75,76 and 77.
My car also has the illuminated pull switch and I think this may be standard as I have come across this switch a few times on Landrovers of this era.
Hope this helps
 

jp928

Active Member
#8
The guts of my question is still out there - is the wiring for the rear screen in the loom if one is fitted?
thanks
 

harveyp6

Well-Known Member
#9
The guts of my question is still out there - is the wiring for the rear screen in the loom if one is fitted?
thanks
I've not seen a UK Series 2 car without a HRW, so if yours has a plain rear screen then I would say that all the wiring for the HRW will be in the loom, and if you have a HRW glass that doesn't work then the wiring will be there and either that or the glass itself is faulty.
 

jp928

Active Member
#10
Mine is an Export car. The HRW is fitted, but there is no switch in place, and hole for it is not cut in the vinyl trim . I will try to trace the wiring from the fuse and see if there is a circuit to earth and then look for switch leads.
thanks
 

roverp480

Active Member
#11
Mine is an Export car. The HRW is fitted, but there is no switch in place, and hole for it is not cut in the vinyl trim . I will try to trace the wiring from the fuse and see if there is a circuit to earth and then look for switch leads.
thanks
Is there a cut out for the switch in the steel panel behind the vinyl ? You may be able to feel it through the vinyl if you press along it with your thumb
 

jp928

Active Member
#13
Have tried probing all the places the HRS may be connected, all showing open circuit. The fuse side shown as going to the switch (SN lead) goes into the loom ...and disappears. I have 2 UW bare male leads, a heavy-ish RY female bullet and a light GN female. None of these show continuity to ground. How do I test the actual screen element - interior D pillar covers need removing, or just good contact of meter probes on the copper end strips? There is NOTHING in my manual about the HRS except changing the bulb in the switch.
Seeing <20 Ohms from LHS (near?) copper end strip to ground, but open circuit from RHS end strip...? Whats the total resistance of the heater supposed to be?
thanks
 
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#14
Don't know if this will help or hinder you but on my car the slate/brown wire feeds a flying inline fuse holder, it then leaves this as a brown/red wire and goes to feed the hrw switch. It leaves the switch as a brown/yellow wire and into the loom and I assume to the rear window. All this magic takes place above the glovebox on the drivers side
 

jp928

Active Member
#15
Sounds like your switch is on the driver's side? Is it a pull or a rocker type?
My slate/brown goes from the fuse block up through a hole in the metalwork above and disappears - tugging indicates its not going to pull out. Maybe I need to look up above the driver's glovebox......hadnt thought of that because there is a hole in the metal panel on LHS that seems right for the switch.
UPDATE - found the two wires on the driver's side! The switch (pull type with light in the knob) has a small piece of bright metal on one side (at the back), and when I pull the switch and ground this bit the knob lights up as intended - real progress! Problem is I cant find any evidence of a position for it on the driver's side, only on the pass side inboard of the glovebox button. No sign of a relay.
Do I need to run leads from driver side back to the left side? My owner's book does not show the switch location anywhere - can somebody verify where the factory switch is mounted please? The WSM on changing the bulb in the switch looks like its on the left near the glovebox button.
thanks
 
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roverp480

Active Member
#16
My RHD 75MY has a rocker switch mounted about 3.5" to the right of the glovebox button , just next to the door opening. , I believe the push /pull was in the same position .
I cannot see, looking at the wiring diagrams ,any relay in the circuit .
 

roverp480

Active Member
#18
I can feel the back of the switch etc just by opening the glove box and pitting my fingers up the back of the panel, so if there is a hole you should be able to feel it
 
#19
My car is a late 72 3500 auto and I have found that the wiring diagram 86.00.01 Sheet 2 in the Rover workshop manual suits my car. It shows the wiring for the heated rear window, switch and relay. The items to look at are 71, 75,76 and 77.
My car also has the illuminated pull switch and I think this may be standard as I have come across this switch a few times on Landrovers of this era.
Hope this helps
My pull switch is in the position that roverp480 describes
 

jp928

Active Member
#20
Mirror reveals a large rectangular hole in the metal (wider than high). My pull switch requires a 12mm hole, so it will have to go through whatever is under the vinyl cover - heavy card material? I suspect the rectangular hole is for the rocker switch. Maybe I will look for one of these.
My wiring is on sheet 7 of 86.00.01, and the only relay on that is for the starter.
Thanks!
 
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