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| Electrical gremlins.. don't add water! |
Rear Plate Light (In Progress)
This was working but the back case had cracked where the screw fixes the front cover on so I ordered a replacement light. The one that arrived expects bullet connectors rather than the lucar connectors that were on the wiring, and after trying red insulated bullets I found it actually wants the solid brass style typically found on British classic cars. So now I'm just waiting for some decent solder to arrive in the post and I'll fit this new plate light.
Brake Lights (Fixed)
These were not working but it was easily tracked down to a faulty switch on the brake pedal. There was infinite resistance across the pins when the switch should be closed. Taking the switch out the circuit brought the brake lights on. I fit a new switch and now the brake lights work.
Tail Lights (OK)
Rear side lights were working.
Indicators (OK, for now)
The lenses had faded and lost most of their amber so I fit two new indicators. I tidied up some broken wiring while I was there by crimping in some new connectors. The right indicator works 9 times out of 10. When it doesn't work, no amount of fiddling with earth or feed wires will bring them on. I haven't checked the output at the flasher unit yet, but I can't get the left side to fail at all so I currently suspect the indicator stalk's Right switch. I will test this and/or replace the stalk with a period correct one at some point. For now, when it doesn't come on, operating the switch again brings it on almost every time.
Panel Lights (In Progress)
When I went to investigate why the panel lights (instrument panel back lights) didn't work I found the bulbs in place and working ok.. but not connected at all to the Panel Lights switch. I traced the wiring to a relay on the bulkhead operating a long length of cable strung down one side of the chassis to where a rear work light was installed. Call me old fashioned but I want the Panel Lights switch to operate the panel lights, and if I want a rear work light I'll route the wiring better than that.. so I removed it all. The panel lights switch also had a broken contact which only closed the switch when manually pushed up to make a connection, so I've ordered a new switch. When it arrives I'll wire it back up to operate the panel lights.
Ignition Switched Circuits (In Progress)
There are a number of circuits that should only operate with the ignition switch on (side lights, indicators, etc.). These circuits will currently close without the key in. There is some wiring for a radio hanging out the bottom of the instrument panel. It looks to me like someone wired that up to operate without the ignition being on, and brought those other ignition switched circuits with it because that's the feed they spurred their new wiring off. I need to remove this bad radio wiring (and the relayed LED illuminated cigarette lighter nearby!) and return those other circuits to be correctly ignition switched.
Wipers (In Progress)
When I went to investigate why the wipers weren't working I found the wiper motor was dead (supplying voltage directly did nothing, and it looked shot), and after some head scratching worked out the the wiper switch could never have worked..
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| Four pins, wrong switch.. |
The wiper switch had four pins on the rear. Looking at the wiring diagram you can see why someone might have bought a switch with four pins (30) and connected the wires like they did; G (fused, switched ignition) to bottom left pin and off again direct to wiper motor, RLG on top right pin and running to feed on wiper motor, NLG on bottom right pin running to auto-park input on wiper motor.. and when that didn't work, they left it there!
But the switch they bought was the wrong type, probably a DPDT (double pole double throw). Single speed wiper motors like this need G (always), plus the NLG and RLG connected to the wiper motor when the switch is off (auto-park), or the G (as always), plus the RLG connected to the wiper motor when the switch is on (wipers on).
Here's a handy diagram from http://www.land-rover-lightweight.co.uk Everything above the dotted line is your wiring and the Wiper switch. Below the dotted line is inside the wiper motor. Where a wire crosses the dotted line, it's where a wire goes into the wiper motor's input connector shown in the right-hand boxout:
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| Wiper motor wiring (click to enlarge) |
When the wipers are on all the time the G feed passes current on RLG which completes a circuit via the motor earth that turns the motor regardless of what the auto-park cam and switch are doing.
When you turn your wipers "off", you still want them to return to horizontal, so you pass G (as always), plus NLG and RLG, which complete a circuit inside and outside the motor and drives the motor only until the cam switch hits the "parked" position on the cam, which then breaks the circuit by opening the park switch inside the motor just as your wipers reach home. (Look, G comes in on pin 4 at the motor, the park cam is turning so the switch is up, the current comes in on G and goes across the park switch, back up NLG to your wiper switch which is connecting the NLG pin with the RLG pin in this position (off for auto-park), then back down RLG to your motor and earths.. all until the park cam presents the park position hole and the park switch opens, breaking the circuit.. and your wipers stop at the horizontal position.)
So the wiper switch needs to connect either G and RLG (always on), or NLG and RLG (auto-park).
The wiper switch that's installed had four pins. By measuring the resistance across the pins I found when the switch was off, no two pins were connected at all, and when the switch was on, the two vertical pairs were connected (top left with bottom left, top right with bottom right). There is no way with this switch to pass G and RLG, or NLG and RLG.
What I need is a single pole double throw (SPDT) switch. And it only needs three pins. G, RLG, and NLG. With an SPDT switch, when it is off two pins will be connected (say, NLG and RLG), and when it is on, one of those two pins will be connected with the third pin (say, RLG and G).
When the switch arrives I'll wire it up and hopefully I will have some working wipers. Because I fit a new motor too.. but that's another post.
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| Work and spot lights wiring and relays. Binned. |
