Restoration: e34 M5 (metallic dolphin)

[Adi]

have started on the switches for the back seats, as well as front seats, some seem to be broken....

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they are actually not too complicated in design, and not to difficult to repair

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when opening switch careful could have quite a few loose parts inside...

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now, question, electronics people, Rick540.....these switches have tiny globes /led stuff

any way of testing that those globes work?

 

[rick540]

have started on the switches for the back seats, as well as front seats, some seem to be broken....

---

they are actually not too complicated in design, and not to difficult to repair

---

when opening switch careful could have quite a few loose parts inside...

---

now, question, electronics people, Rick540.....these switches have tiny globes /led stuff

any way of testing that those globes work?

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Just give them 12V and see if they light up. Looks like a good clean and they will work, make sure the spring is there.

 

[Sankekur]

If they are not working it might also be worthwhile to replace them with amber LED's (in general it might be a good idea to do it with all the globes)

 

[Adi]

just 12v either way, safe to do? These are all 12v? Amber LED's which ones would I get?

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Can I use Led's without a resitor etc etc straight like that?

 

[Sankekur]

Yeah with the globes you can do it either way round.

As far as I know pretty much all of this lighting uses12V (either that or a variable voltage up to 12V, can't remember what the lower value was)
Edit: Though I would just measure anything before making any assumptions.


In terms of the LED's I would go for a known brands like osram or philips (or just ones of the known semi-conductor producers) as for the colour I think it is just amber, not sure if BMW uses a special kind of amber LEDs

With the LED you will have to fit a resistor, as I don't think any of the light driver is current limited (well at least not within the operating limits of most LEDs)

 

[Adi]

but the guys at Communica should know? Shall ask after having tested the switches......hope have to not open them again.......getting those balls in the right place is a mission

 

[Sankekur]

Yeah they have a decent amount of knowledge......(though I would still be careful)

 

[Adi]

will test on a spare switch if lights work, lets see

 

[rick540]

If use use LED's the superbright amber Communca sell is very close, use an 1800Ohm resistor to tone them down a bit

 

[Adi]

thank you, so far only taken off one door panel.....will be doing some fixing tonight!

 

[Adi]

door panel is off, lots of cleaning, and most brakets are missing.

I know where I can get the door panel clips, any suggestion for the bottom part where the clips go into.

Most of mine are lost, where can I get others?

 

[Raybimmer]

Rick does the led have an angle ov light output , i.e. straight or 90 degrees etc . Will a 1/4 watt resistor at 18K be ok ? Soldered on the positive leg of the resistor ?
Adi maybe a little grease on the balls before assembly will help .
Are the switches M5 specific ?ok just checked realoem they are e34 and e32 applications - thigh support switch .

 

[rick540]

@ Adi find some old E34 door covers and remove the plastic bits, they will be able to be glued onto yours with Pratley steel.

@Ray The LED does output a narrow 30 degree beam of light but I sand the LED with 80 grit sandpaper and that helps to diffuse the light very well. Using Ohms law 14V/1800Ohm = 10 Miliamp. 0.010 * 14V = 0.14 Watt, so even the smaller 1/8 watt resistor will work. The resistor can be soldered to either positive or negative leg doesn't matter.

 

[Sankekur]

You actually also need to subtract the forward voltage drop across the LED from the supply voltage to get the voltage drop across the resistor for doing the power calculation.
The forward voltage is usually >1.4V (will be less for LED's that emit in the IR range), it is around this value for a red LED and increases for decreasing wavelengths of light emitted (higher voltage for higher energy light)

 

[rick540]

You actually also need to subtract the forward voltage drop across the LED from the supply voltage to get the voltage drop across the resistor for doing the power calculation.
The forward voltage is usually >1.4V (will be less for LED's that emit in the IR range), it is around this value for a red LED and increases for decreasing wavelengths of light emitted (higher voltage for higher energy light)

I know that but the forward voltage drop affects the calculation only a small amount and I was trying to keep it simple.

 

[Sankekur]

You actually also need to subtract the forward voltage drop across the LED from the supply voltage to get the voltage drop across the resistor for doing the power calculation.
The forward voltage is usually >1.4V (will be less for LED's that emit in the IR range), it is around this value for a red LED and increases for decreasing wavelengths of light emitted (higher voltage for higher energy light)

I know that but the forward voltage drop affects the calculation only a small amount and I was trying to keep it simple.

True, and the addition of the voltage drop across the LED calculation will actually just show that the power rating of the resistor needed is actually lower still :rollsmile:

I usually use 10% as a measure of a small effect, less that 10% is a small effect and larger will probably need to be taken into account.

So Rick you say that the standard high brightness amber LEDs are similar in colour to the BMW amber?

 

[rick540]

You actually also need to subtract the forward voltage drop across the LED from the supply voltage to get the voltage drop across the resistor for doing the power calculation.
The forward voltage is usually >1.4V (will be less for LED's that emit in the IR range), it is around this value for a red LED and increases for decreasing wavelengths of light emitted (higher voltage for higher energy light)

I know that but the forward voltage drop affects the calculation only a small amount and I was trying to keep it simple.

True, and the addition of the voltage drop across the LED calculation will actually just show that the power rating of the resistor needed is actually lower still :rollsmile:

I usually use 10% as a measure of a small effect, less that 10% is a small effect and larger will probably need to be taken into account.

So Rick you say that the standard high brightness amber LEDs are similar in colour to the BMW amber?

They are very very close, The BMW colour in nanometers is actually perfect amber, cant remember the exact figure but looking at the data sheet the Communica "king led" or something HB amber was only 25nm off this

 

[Raybimmer]

Might be a good idea to fit new leds to all switches...........yes I know its a mission but worth the effort .

 

[Sankekur]

You actually also need to subtract the forward voltage drop across the LED from the supply voltage to get the voltage drop across the resistor for doing the power calculation.
The forward voltage is usually >1.4V (will be less for LED's that emit in the IR range), it is around this value for a red LED and increases for decreasing wavelengths of light emitted (higher voltage for higher energy light)

I know that but the forward voltage drop affects the calculation only a small amount and I was trying to keep it simple.

True, and the addition of the voltage drop across the LED calculation will actually just show that the power rating of the resistor needed is actually lower still :rollsmile:

I usually use 10% as a measure of a small effect, less that 10% is a small effect and larger will probably need to be taken into account.

So Rick you say that the standard high brightness amber LEDs are similar in colour to the BMW amber?

They are very very close, The BMW colour in nanometers is actually perfect amber, cant remember the exact figure but looking at the data sheet the Communica "king led" or something HB amber was only 25nm off this

Think it is king bright or something like that........either way, that is good to hear, since I have had this idea for a while now to change the globes used on the e34 stuff to LED's (Main reason being the interior lights on the e34 feels so dim compared to say the e46)

Sorry for the off-topic :wrongforum:


If LED's are used and they are still working I would personally not change them.

 

[Adi]

Thanx will test, when assembling the car again, each switch, and see if the lights work, if not attempt the repair.....

If they work would hate to open a switch to try and replace with Led's only to break the switch in the process.

Progress made today, second door panel removed and cleaned. What will need to happen is that the door panels are so weak that I will need to re-inforce them with the kevlar stuff I used on my e12 boot pieces...unfortunatly, its finished so I can get on Tuesday only......so Tuesday evening both back panels should be mint again.....

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Question: Both doors at the bootom show signs of some rust, its easy to fix but what about inside the door, how can I get that rust cleaned, more importantly how do i ensure it does not spread further from the inside?
Was thinking sand paper, then rust converter and then spray out with primer on the inside. Any ideas?