Relay 292, a technical study.
Posted: 05 Dec 2017, 09:52
Lots of folks seem to have issues with relay 292 headlight buzzer...
here's my story.
If you just want an easy solution read the red bit below.
I got myself a relay 292 headlight buzzer and plugged it into position 7.
It didn't work, (yes I have a relay 99 fitted)
And my rear fog light didn't work.
So I dug out the wiring diagrams to figure out what's going on.
first off, the pinout for relay 292-
pin 86-ignition + (detects ignition on)
pin 85-ground
pin 58-light switch (detects lights on)
pin R- works the same as pin 58
When you pulg it into position 7 it is connected like this...
pin 86 to foglight switch,
pin 85 to ignition + (x relay contact)
pin58 to lights
pin R to ground (ie: not used.)
So it works like this-
It detects lights-on via pin 58,
pin 86 is basically open circuit so it thinks ignition is off all the time.
and for it to buzz it needs to ground it's pin 85 via relay 99 when x relay is off, ie: when ignition is off.
This is not quite how it was designed to work but it gets away with it if you're lucky.
BUT the rear fog light will never work, there's no power getting to the fog light switch.
To get the rear fog light to work you need either a proper relay in position 7 or the little brass jumper that connects pin 4 to pin 3 on the relay socket to get power to the fog light switch.
If you have front fog lights you need a proper relay in position 7.
My solution was to forget plugging it into position 7 and wire it separately.
like this-
Pin 86 to fuse box terminal G2. (or G5)
pin 85 to a chassis screw. ( I used one of the glove box bracket screws)
pin 58 to fuse box terminal G9.
Pin R left disconnected.
It works.
And so does my fog light if I leave the little brass jumper or a normal 4 pin relay in position 7.
And it doesn't rely on relay 99.
I have another solution which involves rewiring buzzer 292 internally so it will work properly in position 7 and work a rear fog light too.
But is it really worth it?
here's my story.
If you just want an easy solution read the red bit below.
I got myself a relay 292 headlight buzzer and plugged it into position 7.
It didn't work, (yes I have a relay 99 fitted)
And my rear fog light didn't work.
So I dug out the wiring diagrams to figure out what's going on.
first off, the pinout for relay 292-
pin 86-ignition + (detects ignition on)
pin 85-ground
pin 58-light switch (detects lights on)
pin R- works the same as pin 58
When you pulg it into position 7 it is connected like this...
pin 86 to foglight switch,
pin 85 to ignition + (x relay contact)
pin58 to lights
pin R to ground (ie: not used.)
So it works like this-
It detects lights-on via pin 58,
pin 86 is basically open circuit so it thinks ignition is off all the time.
and for it to buzz it needs to ground it's pin 85 via relay 99 when x relay is off, ie: when ignition is off.
This is not quite how it was designed to work but it gets away with it if you're lucky.
BUT the rear fog light will never work, there's no power getting to the fog light switch.
To get the rear fog light to work you need either a proper relay in position 7 or the little brass jumper that connects pin 4 to pin 3 on the relay socket to get power to the fog light switch.
If you have front fog lights you need a proper relay in position 7.
My solution was to forget plugging it into position 7 and wire it separately.
like this-
Pin 86 to fuse box terminal G2. (or G5)
pin 85 to a chassis screw. ( I used one of the glove box bracket screws)
pin 58 to fuse box terminal G9.
Pin R left disconnected.
It works.
And so does my fog light if I leave the little brass jumper or a normal 4 pin relay in position 7.
And it doesn't rely on relay 99.
I have another solution which involves rewiring buzzer 292 internally so it will work properly in position 7 and work a rear fog light too.
But is it really worth it?