is there a 12v switched wire sunroof / dome light?

[slowcar88]

was trying to hardwire a radar detector and couldn't find a 12v switched in the sunroof switch or even in the dome light / visor light.

does anyone know if there is a 12v switched wire (tied to ignition) that I could tap into - and what color it would be?

[m60power]

Your best chance is probably the sunroof switch. Take a look at the E32 wiring diagrams, you should be able to figure out a good option for ignition switched 12v power:

https://www.armchair.mb.ca/~dave/BMW/e32/

[slowcar88]

Your best chance is probably the sunroof switch. Take a look at the E32 wiring diagrams, you should be able to figure out a good option for ignition switched 12v power:

https://www.armchair.mb.ca/~dave/BMW/e32/

thanks. ill dig in / take a look.

[shogun]

interior lights, sunroof , electric windows are controlled by the ZKE = central chassis electronics = GM. When you unlock the car, these functions are there = have power.
for example
interior light goes from terminal 30>to RM = relay module>>>GM general module http://www.e32-schrauber.de/bmw/daten/zke/image055.jpg
sunroof + electric windows have power on US cars when the driver door is opened via terminal 15 http://www.e32-schrauber.de/bmw/daten/zke/bild17.jpg
from ZKE details in German language http://www.e32-schrauber.de/bmw/s-zke.htm

[slowcar88]

interior lights, sunroof , electric windows are controlled by the ZKE = central chassis electronics = GM. When you unlock the car, these functions are there = have power.
for example
interior light goes from terminal 30>to RM = relay module>>>GM general module http://www.e32-schrauber.de/bmw/daten/zke/image055.jpg
sunroof + electric windows have power on US cars when the driver door is opened via terminal 15 http://www.e32-schrauber.de/bmw/daten/zke/bild17.jpg
from ZKE details in German language http://www.e32-schrauber.de/bmw/s-zke.htm

thanks. do you know if it take time for the car to power down after engine is shut off, keys removed, and locked?

when i tapped into the only working power in the dome light wires, it seems to be always on (but i only waited about 30 seconds)

[shogun]

sleep mode testing instructions mention 16 minutes after you locked the car or did not open the doors etc:

Maximum closed current by vehicle: E31 50mA, E32 50mA, E34 40mA,E36 30mA,E38 50mA,E39 40mA,E46 40mA,E52 50mA, E53 40mA, Z3 30mA - Performing Closed Current Draw Test
• Select proper measuring device (DISplus, MoDic or DVOM), Remember amperage draw in excess of 10A will damage DVOM. Use inductive amp probe of DISplus when amperage draw is high. When using DISplus inductive probe, clamp on negative battery cable with arrow pointing away from battery. Switch off all consumers. (It is not necessary to disconnect B- from body when using inductive probe)
• Connect (-) test lead to negative battery terminal and (+) test lead to a known good ground.
• Ensure all systems are OFF !
• Be sure DVOM is on and set in proper mode.
• Disconnect battery ground lead from body.
• Observe meter reading, wait 16 minutes for vehicle to enter sleep mode.
• Identify faulty circuit by disconnecting fuses, relays, control modules or connectors, observing meter readings.
• Defective circuit is found when current is below maximum closed current for vehicle being tested. use this link for more details http://www.e38.org/battery.pdf

I connected my radar with the power cable to the radio and the cable comes out between dash and A-pillar https://www.7-forum.com/bild.php?bil...=Links-Verkehr in Japan&cpy=Erich (7er.com-Forumsmitglied)

[slowcar88]

Thanks shogun. I’ll try it out and report back

[E32FAN]

Page 6330-03 shows the Dome Light wiring.

BRN/RED is HOT AT ALL TIMES. YEL/BLU is switched to Gnd by the Relay Module when the car is running.

So you can get radar detector 12V Power from BRN/RED and GND from YEL/BLU.

[slowcar88]

Thanks. Need to pull the dome light but I don’t recall seeing brn/red and yel/blu

Edit: is it brown or red? Yellow or blue? Or has to be brn/red combo wire

For reference, here are the sunroof wires

[Timm]

The E32 has the same dome light as the E31 - I show where to pick up the switched live in this video:

[E32FAN]

Thanks. Need to pull the dome light but I don’t recall seeing brn/red and yel/blu

Edit: is it brown or red? Yellow or blue? Or has to be brn/red combo wire

For reference, here are the sunroof wires

The white connector with 4 pins is X336. It is shown on page 8500-09.

Pin 1 is closest to us and it is BRN.
Pin 2 is RED/BLK
Pin 3 is YEL/BLU
Pin 4 is BRN/RED

[erachner]

The E32 has the same dome light as the E31 - I show where to pick up the switched live in this video:

Hi Timm,

Speaking as a grateful learner who has benefited from your technical guides, I wanted to share a caution here: although the dome/map light assembly is the same part between the E32 and the E31, the manner in which its circuits are powered is, in fact, different!

On the E31, you can pick up power from the dome light's manual switch and rely on the consumer cutoff relay to cut power to that circuit 16 minutes after the car has been parked/locked. However, I've learnt from direct experience that on the E32, the dome light's manual switch is powered at all times - even long after the car has been parked! In other words, it is possible to leave the E32's dome light manually switched on for hours and potentially run the battery down, because unlike the E31 there is not a consumer cutoff to prevent you from doing so.

So on the E32, if you want a switched power source near the sunroof / rear view mirror, the dome light's manual circuit isn't what you want - it's not switched.

[erachner]

Page 6330-03 shows the Dome Light wiring.

BRN/RED is HOT AT ALL TIMES. YEL/BLU is switched to Gnd by the Relay Module when the car is running.

So you can get radar detector 12V Power from BRN/RED and GND from YEL/BLU.

E32FAN,

I'm very new to all this and not very confident in my understanding yet, so please forgive me if I'm confused and mistaken, but -- are you sure that the YEL/BLU wire on pin 3 is connected to ground whenever the car is running? My understanding from both the diagram and from experimenting with a voltmeter is that pin 3 only goes to ground when the dome light is meant to illuminate automatically, such as when a door is opened. If pin 3 went to ground at all times when the car was running, then wouldn't switching the dome and reading lamps to "automatic" cause them to be on at all times the car is running, because pins 2 (RED/BLK) and 4 (BRN/RED) are both hot at all times and the "automatic" switch position connects the lamp bulbs to pin 3?

Again, please excuse me if I'm mistaken - I'm not trying to bring confusion to the forum, and all I know for sure is that I'm definitely confused, even if I'm right

Thanks,

Eric

[E32FAN]

E32FAN,

I'm very new to all this and not very confident in my understanding yet, so please forgive me if I'm confused and mistaken, but -- are you sure that the YEL/BLU wire on pin 3 is connected to ground whenever the car is running? My understanding from both the diagram and from experimenting with a voltmeter is that pin 3 only goes to ground when the dome light is meant to illuminate automatically, such as when a door is opened. If pin 3 went to ground at all times when the car was running, then wouldn't switching the dome and reading lamps to "automatic" cause them to be on at all times the car is running, because pins 2 (RED/BLK) and 4 (BRN/RED) are both hot at all times and the "automatic" switch position connects the lamp bulbs to pin 3?

Again, please excuse me if I'm mistaken - I'm not trying to bring confusion to the forum, and all I know for sure is that I'm definitely confused, even if I'm right

Thanks,

Eric

Eric,

My apologies - you are correct! The E31 has K72 and K73 Consumer Cut-Off Relays (page 6330.0-02), but E32 does not.

The E39 and E40 left or right rear reading light assemblies (page 6330-02) have HOT IN RUN OR START on pin 1, Violet/Wht and Gnd on pin 1, Brn. You could feed a cable under the headliner trim, or possibly mount your device in the rear.