I’d been interested in it.
Gauging interest / A Dedicated Headlamp Harness with Fuses and Relays / Concept / Demand ?
- Thread starter paul cain
- Start date
Years ago, there was ban effort in the industry to move to 42 volts (the "12V" battery is actually 14 volts, so three of them in series makes 42 volts) https://www.powerelectronicsnews.com/whatever-happened-to-the-42-volt-bus/
This ultimately didn't go anywhere because the difficulty of changing was just too great
I rewired my 635 headlamps using a pair of relays in order to use dual filament outer lamps. What this six filament system did was to feed current to the low beam outer filaments in the low beam mode, and then to energize the high intensity outer filaments and the inner low beams in the high beam mode. SO the inner lamps came on to fill in the front region in the high beam mode, but at any given time only one of the outer filaments was energized. Worked great, and it relied on the relay controlled power for the headlamps (standard inthe 635).
Here is the circuit I developed.
That said, I'd definitely be interested in a professionally made improved E9 headlamp harness.
Here is the circuit I developed.
That said, I'd definitely be interested in a professionally made improved E9 headlamp harness.
Attachments
I also second the idea of a power window control unit.
The windows seem to be a chronic issue on these cars. Routing a fused 12 volt line to each motor and using a relay located at the motor would add some wiring, but it would assure adequate current to the motors, and it would also reduce the current in the flimsy window switches in the console. I suppose a really slick solution would be to just route 12 volts to each window motor and use a Bluetooth controller in the console to send signals to each motor controller. That would eliminate some wiring! Not very period correct though. The other approach would be to use a LIN controller that superimposed the window commands on the 12 volt window current line. Then use the console switches to tell the master LIN controller which window to control. Probably the most difficult part of that would be to handle arbitration, so the system would not get confused if two switches were activated at the same time.
The windows seem to be a chronic issue on these cars. Routing a fused 12 volt line to each motor and using a relay located at the motor would add some wiring, but it would assure adequate current to the motors, and it would also reduce the current in the flimsy window switches in the console. I suppose a really slick solution would be to just route 12 volts to each window motor and use a Bluetooth controller in the console to send signals to each motor controller. That would eliminate some wiring! Not very period correct though. The other approach would be to use a LIN controller that superimposed the window commands on the 12 volt window current line. Then use the console switches to tell the master LIN controller which window to control. Probably the most difficult part of that would be to handle arbitration, so the system would not get confused if two switches were activated at the same time.
jmackro
Well-Known Member
Man, you're really complicating this problem! There are already wires running from the console switches to the door and rear seat area. Yes, those wires and the switches are undersized for carrying the full current of the motors, but despite any corrosion on their connectors, they can easily deliver the few milliamps that the relays draw. So the problem of sending the "UP-DN" signal to the motors is solved.
If you want to go high tech, I suppose that solid state relays would be more 21st Century than the old click-clack type. But unless you go through a lot of toll booths, you are unlikely to wear out a mechanical window relay in your lifetime.
I read it four times and I got lost five...
Yeah, my thought here was to avoid adding an extra power wire to each motor. I suppose the easiest solution would be to simply locate the window relays in the console and use the existing wiring. The wires are not really the limiting factor. it is ultimately, IMO, the switches. OTOH, you could run a larger power wire out to each motor, locate a relay there, and control it using the existing wiring.. Sort of a heavy handed solution, but that would assure adequate power to the motors.
you don't have to run 4 complete runs from the battery to each motor - you need 1 major run into the car from the battery and distribute it to each of the 4 motors. my thought was to use the existing wiring + switches to power the relay to control the motors. this is also diagrammed in the FAQ - https://e9coupe.com/forum/threads/e9-parts-dimensions-drawings-technical-info-and-models.43743/ ... thread 8. now this is a drawing just for the sardine motors.
Yeah, I could have been clearer on that.
The issue has to do with using four filaments vs six. The four filament setup has the high beams on the outside of the four lamp set, and the low beams on the inside. I believe the idea is that when the high beams are on the inner low beams are also on, but when the high beams are off, the only low beam lamps are in the inner spaces, which not only looks weird, it doesn't do a very good job of lighting the edges of the road.
The six filament setup has a low beam filament in each lamp, and the high beam filament in the outer lamps (so the outer lamp has two filaments, high and low). This gives you three lighting options:
1) High Beam: Outer high beam filaments on, inner low beam filaments on; Low Beam: Outer low beam filaments on, out high beam filaments off, inner low beam filaments off. This is the setup my relay circuit provides.
2) High Beam: High and Low beam outer filaments on (heats up the outer lamps a LOT), inner low beam filaments off. Low Beam, all four low beam filaments on.
3) High Beam: Outer High Beam filaments on, All Low beam filaments off. Low Beam: High beam filaments off, all four low beam filaments on. (not as complete lighting in high beam, and excessive lighting in low beam).
So the circuit I posted sets up the six filaments in configuration 1 above.
I am certainly not the expert here, nor the Stern!
I am simply the fire starter. You folks are off with some excellent replies on this topic. The expert here is Galahad.
I am confident he is taking in all your suggestions and schematics. Lets please stay focused on the topic of protecting and improving the headlamp circuit (redesigning the window lift motors is a more complicated and separate topic -ask me how I know.) I encourage one of you to start a dedicated thread on window lift motors.
For the redesigned headlamp wiring there should be some elegant, modern solutions. Ample amps (sorry) are available at the + side on the battery, white and yellow wires for the high and low beam are inches away from the battery. I for one would want to do a short run with a heavy gauge wire off the battery + and into this new relay and fuse box, then new (heavier than OEM gauge) wiring out to each headlamp, with (4) new 3 pin mating connectors. One solution would be to repurpose your old hi and low beam wiring with the 3 pin connectors and plug them straight into the new box as the low current trigger for the new relays. Then use fresh wiring out to the four bulbs. Last item, add a really beefy ground circuit. My two cents -gents.
Yeah, that's probably the simplest way to do it. The battery line would need to split somewhere in the instrument panel, and run to the doors and to the rear sides. Since all windows are seldom activated at the same time, the single B+ wire only needs to be large enough to support one motor with some margin.
That said, it might be fun to figure out how to modernize the electric windows, since they are all in all pretty awful.
1) Larger motors with more direct current sourcing (the discussion we have been having).
2) Auto up/down, with auto stop by reversing the switch momentarily
3) Auto Stop at top and bottom
4) Anti pinch
2-4 require some level of processing and some sort of sensors. Most car window systems use motor stall current to sense a pinch. They either have position sensors to sense top and bottom, or they use stall current for that too. If they have position sensors, then they can differentiate between a top/bottom stop and a pinch, so then the pinch automatically backs off the window a bit, whereas top/bottom just stops. I would do this by placing a sensor/controller at each motor, and then using a LIN network to send up/down commands to the window controllers. Basically pressing "up" would start the window up, and it would just keep going up until it stopped at the top, or there was a short "down" signal, which would indicate a stop. A second "down" signal would then send the window down...Same thing in reverse for down. Pretty simple state machine, easy to implement in a PIC microcontroller, which can be found with a LIN interface.. so basically a one chip and one relay module for each window.
All very interesting, but I am not sure I want to depart "too" much from the original...
Yeah, this is basically what I ended up with on the 635. The relays are right next to the battery on the left front of the engine bay. Mine was hand made, but a nice well structured controller (thinking something with relay sockets to avoid a bunch of spade connectors to the relays), and crisp new wiring would be a huge improvement. Even on a 1980 car the wires were pretty crusty!I am certainly not the expert here, nor the Stern!
The expert here is Galahad.
I am confident he is taking in all your suggestions and schematics. Lets please stay focused on the topic of protecting and improving the headlamp circuit (redesigning the window lift motors is a more complicated and separate topic -ask me how I know.) I encourage one of you to start a dedicated thread on window lift motors.
For the redesigned headlamp wiring there should be some elegant, modern solutions. Ample amps (sorry) are available at the + side on the battery, white and yellow wires for the high and low beam are inches away from the battery. I for one would want to do a short run with a heavy gauge wire off the battery + and into this new relay and fuse box, then new (heavier than OEM gauge) wiring out to each headlamp, with (4) new 3 pin mating connectors. One solution would be to repurpose your old hi and low beam wiring with the 3 pin connectors and plug them straight into the new box as the low current trigger for the new relays. Then use fresh wiring out to the four bulbs. Last item, add a really beefy ground circuit. My two cents -gents.
The key question is what is the filament configuration (see my post #29 above)...