Confused about how the E36 HAZARD switch is wired up. Please help.

[JuBu]

Ok, so my alarm install is 99.99% complete, with the exception of the HAZARD LIGHTS flash when you arm/disarm and when the alarm is triggered. I may even leave it like this to maintain the factory/OEM look, but as a matter of pride if you will, I'd like to tackle this wiring problem.

So, during my alarm install, I snaked the HAZARD LIGHTS wire coming from the Alpine alarm brain all the way under the shift boot area and to the HAZARDS switch. There, I found 4 wires going to the HAZARD switch: BLUE/GREEN, BLUE/BROWN, RED/GRAY, and BROWN.

According to the Bentley Manual:
RED/GRAY is the power to the button (controls the light used to light up the button at night).

BROWN is the ground wire.

BLUE/GREEN is the driver's side hazards.

BLUE/BROWN is the passenger side hazards.

So, with that all figured out, I bought two diodes and connected two new pieces of wire to the single HAZARDS WIRE coming from the Alpine alarm brain. Now, the end looks like a "Y," with each branch on the "Y" being diode isolated. One side of the branch was tapped into the BLUE/GREEN and the other side was tapped into the BLUE/BROWN. When I went to arm the alarm, only the driver's side blinked. I checked all connections and everything was ok. The hazards are not broken since I depressed the switch and both sides turned on.

What am I doing wrong?



Thanks,
Justin

[ASCH MAN]

You need a relay off of the Alpine alarm. Some alarms you can switch from a positive to a negative pulse on items like this, but not on the Alpine.

I believe that the alarm will send a positive flash, but you need it to ground instead. You can use the trigger right in the factory harness.

The only problem you will have is that it flashes a flashing circuit, so the hazards will flash, but you will get a small double flash as it holds it just long enough for the factory flashing circuit to cycle once. It works fine, just a little annoying.

AvusBlue took the more professional route and ran the wires to the headlight switch. Ask him for his writeup, it is very nice.

[JuBu]

Originally posted by AudioMan
You need a relay off of the Alpine alarm. Some alarms you can switch from a positive to a negative pulse on items like this, but not on the Alpine.

I believe that the alarm will send a positive flash, but you need it to ground instead. You can use the trigger right in the factory harness.

The only problem you will have is that it flashes a flashing circuit, so the hazards will flash, but you will get a small double flash as it holds it just long enough for the factory flashing circuit to cycle once. It works fine, just a little annoying.

AvusBlue took the more professional route and ran the wires to the headlight switch. Ask him for his writeup, it is very nice.

DAMN...I totally forgot about the negative/positive inputs. Thanks AudioMan.

Oh well, the lights aren't that big of a deal, I guess I'll put that off until another time. Anyways, I kinda like the no flash deal.

-Justin