Oilpressure noise warning? Options

[falcor75]

As I experienced a blown hose to my front oil cooler yesterday I'm now quite aware that just the little green oil pressure light isnt enough. I would like to add an audio warning aswell.

Has anyone done this? What parts did you use and how did you connect it?

[jim_hoyland]

A VW/Audi chime relay will do the trick. They can be triggered by either ground circuits or 12v circuits. The one I have can process 3 or 4 Seperate signals and chime,
At present. I have my driving lights connected to the chime relay; so if I turn off the ignition and forget to switch off the light switch, the relay chimes
Part is listed as: Audi-VW 443-919-439-C (or A)
Relay Pin-Outs:
This is not vehicle specific, but I'm planning to replace the Central Processing Unit in my FC with modular components (pluggable relays and flashers) so that I don't have to shell out over $100 for a board that integrates the horn relay, alternator relay, chime and seat belt timer, nor $86 for a proprietary 7-pin flasher relay.

One of the building blocks is an Audi/VW 443-919-439-A chime relay bought used off eBay for $8 shipped. This is a self-contained unit with isolated ground and +12V inputs, two timed ground ouputs for a seat belt warning lamp and seat belt switch, and two different pitched tones. These units were used in the the 1990s Audi 80 and other models.

Pins 15, 85, 86, L and 31 are 6.3mm terminals while R, 58, RK and G are 2.8mm. Hella socket HL87123 is a 9-pin and a perfect fit.

Pin 31 is the relay's system ground. This pin must be grounded at all times for the relay's functions to work.

Pins R, 58, and 85 are +12V inputs, all isolated from each other. R is actually an input from the Audi's radio. Any of these pins run the chime only when pins 86 or TK are grounded.

Pin 15 is a +12V input that is also isolated from the other +12V inputs with one difference. When this input is energized, pins L and G go to ground for 10 seconds then disconnects. Only pin 15 has this feature, the others are chime-only.

Pin L is a timed ground output. It is used to hook up to the seat belt warning light. Pin G is another timed ground output, it connects to pin 86 if the seat belt switch is closed.

Pins 86 and TK are both ground inputs for the chime. They both emit a chime when any of the four +12V inputs are energized. However, pin 86 is higher pitched than TK. Like the +12V inputs, both are isolated from each other.

So, you can either use the unit's build in isolation to hook up your light switch, key-in switch, seat belt, etc using the Hella 9-pin relay socket, or use a conventional 5-pin relay socket and external diodes for your inputs. You can't really go wrong either way.

Since I already have the Hella 9-pin panelmount relay socket, I'd rather take advantage of the all the unit's built-in features than add additional components.

Since the seat-belt switch in an FC RX7 is actually tied to the seat belt light wire, I only need to use the L terminal. So, when all is said and done, only pins R and G will be unused. To ensure that the unit doesn't chime when the door is opened, I plan to use a DEI 528T timed relay inline between ign-switched power and Pin 15.

See the link below for the pin arrangement

http://www.rx7club.com/attachments/interio...in-out-rev2.jpg