Help with dash illumination 1988 M5

[York]

Can someone please share information on the lighted instruments/ controls on dash. Color code for any would help.
What got this started is my headlight switch is not illuminated and I thought it would be.
My 1972 bmw 2002 headlight switch is not but, I thought by 1988 they would be.
I have a wire diagram and the search begins this week.

[Blue Shadow]

www.e38.org/e28 middle of the left column, Electrical Troubleshooting Manual (ETM) has all that info for you.

[BMWCCA2]

Couldn't be something as simple as a bulb, could it?
You did check that, right?

[Shawn D.]

The switch assembly is illuminated, in that the three symbols to the right of the lever light up, but the lever itself does not light up. If the former isn't lit, start by changing the bulb as BMWCCA2 suggested. If you're trying to "fix" the latter, there's nothing to fix.

[York]

Check the headlight switch wiring and connections using the wire diagram to identify any issues, ensuring proper illumination.

Thank you

[York]

Couldn't be something as simple as a bulb, could it?
You did check that, right?

How would I know?
I’m still trying to understand which items have light bulbs
My headlights have none , my ac does

[York]

The switch assembly is illuminated, in that the three symbols to the right of the lever light up, but the lever itself does not light up. If the former isn't lit, start by changing the bulb as BMWCCA2 suggested. If you're trying to "fix" the latter, there's nothing to fix.

I don’t even know which are supposed to have lights
But, thanks for taking the time to reply

[Shawn D.]

I don’t even know which are supposed to have lights

There's a single bulb (which is why I phrased it as "the bulb") that lights the right side of the headlight switch assembly. To clarify, were you only asking about the headlight switch, or the entirety of what's supposed to light up on/around the dash?

You can also look on RealOEM.com, BTW.

[York]

I don’t even know which are supposed to have lights

There's a single bulb (which is why I phrased it as "the bulb") that lights the right side of the headlight switch assembly. To clarify, were you only asking about the headlight switch, or the entirety of what's supposed to light up on/around the dash?

You can also look on RealOEM.com, BTW.

I’m trying to understand what is illuminated in the
Entire dash , not just the headlights.
I looked at a old sales brochure but, they don’t
List each and every item that has lighting.
Is there such a list
And by the way, thanks for taking the time to help

[Shawn D.]

I looked at a old sales brochure but, they don’t
List each and every item that has lighting.
Is there such a list
And by the way, thanks for taking the time to help

You're welcome.

Sales brochures are a pretty terrible way of figuring out stuff like this.

There's no list, but here's what's lit and how many bulbs:

- headlight switch, one bulb
- fog light switch, one bulb
- instruments, two bulbs
- OBC, two bulbs (in one assembly)
- radio (lit internally by ?? bulbs)
- HVAC, lit by one bulb for each knob and one bulb for each slider, plus one bulb in the AC button
- lighter/ashtray, one bulb attached to the side of the lighter assembly
- window switches, two bulbs each ('87 and '88 only)

[Blue Shadow]

There's no list, but here's what's lit and how many bulbs:

All are shown in their circuits in the ETM linked above.

[York]

If all the illumination bulbs are the same , could you suggest a source and are there led bulbs which would be better ?

[RetiredDoc]

I posted this more than 10 years ago but can’t find my list. So to get you started from memory the three HVAC slider controls, the headlight switch, the OBC display itself and the OBC buttons (different bulbs), the radio (I believe there are 2 bulbs since one side of my radio display has gone dark), snowflake AC button when engaged, all of the power window switches and sunroof switch (this varies as some models came with unlighted window switches), the instrument panel by bulbs above it in the cluster, both the temp and fan speed knobs, hazard light switch, and rear window defrost switch. The M5 has heated seats so those buttons are also illuminated.

[Shawn D.]

If all the illumination bulbs are the same ,

You'll have to look up the P/Ns on RealOEM to determine that.

are there led bulbs which would be better ?

No, because LEDs do not dim linearly as incandescents do. There are probably some that will function, but will not have the same adjustability.

[York]

If all the illumination bulbs are the same ,

You'll have to look up the P/Ns on RealOEM to determine that.

are there led bulbs which would be better ?

No, because LEDs do not dim linearly as incandescents do. There are probably some that will function, but will not have the same adjustability.

How do I dim ?

[Blue Shadow]

How do I dim ?

The LEDs don't really dim. On or off.
Incandescent light bulbs dim with the wheel on the headlamp switch.

[Shawn D.]

How do I dim ?

You dim LEDs by implementing pulse width modulation (PWM). Doing so would require a rework of the dimming circuit. If you want to do that, you'll have to figure it out yourself.

FWIW, this is the only off-the-shelf interface I know of, but it only handles six of their gauges. How many LEDs that entails is something I don't know. You'll have to research that.

[York]

When I asked, how do I dim ? I meant generally speaking
Not led’s

[Shawn D.]

Just look at your light switch. It's pretty obvious.

[Blue Shadow]

When I asked, how do I dim ? I meant generally speaking
Not led’s

I answered that two posts above your post asking how to dim.

[Philo]

I love it when Shawn weighs in on the conversation. So detailed, love it ! The dash lighting issue is something I need to look into as well. My RPM side light is out, sliders aren't working, some window button lights are out.

good kick in the butt thread..

[Mike W.]

I love it when Shawn weighs in on the conversation. So detailed, love it ! The dash lighting issue is something I need to look into as well. My RPM side light is out, sliders aren't working, some window button lights are out.

good kick in the butt thread..

I thought the window switch bulbs were NLA. Back when they were common in the yards you could go thru and grab a couple if you had one burnt out, but that was then and this is now. Might be available or a substitute, there's so much more stuff online than there was in the early 2000's.

[DavidE9]

FWIW, I just bought a few replacement window switches off eBay. Complete garbage.

https://www.ebay.com/itm/134441538272

I tried to fix my switches, but I couldn't get them open:

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