What is the relay?
 

this is located under the driver side dash. It is connected to an end of a cable...which I though was odd.

not sure where it leads..what is if for?

http://forums.pelicanparts.com/uploa...1737936596.jpg
http://forums.pelicanparts.com/uploa...1737936596.jpg

Turn on your flashers or blinkers and see if it clicks..

What model, year, engine?
The blinker/hazard relay is rectangular.
US/CAN/JPN/ROW?

you will find the answer here
http://forums.pelicanparts.com/porsche-911-technical-forum/665204-turn-signals-work-but-wont-blink.html

year model
 

1981 carrera, 3.2

ok, but not enough information for me.
So it's a 1981 tub with a swapped engine from a 3.2 Carrera? Or did you stroked the original 3.0 SC engine to a 3.2? Still CIS? Or Motronic ECU? US or ROW?

Background: That round relay is standard on G body cars up to 1989. In the area behind the dashboard it may remain from the original SC engine to manage the rev limiter...that's I need to know as much details as possible...

Thomas

swapped engine? no its a 1981 911 SC. not carrera

The base connector for the relay looks like it was mounted at one time in a body opening.

do you happen to have the wiring headlight diagram for an 1981 911?

https://classickabelboomcompany.com/wiring-diagram-porsche/

Ok, when the car is an US model with the 930/16 engine, then I suppose that this is the rev limiter relay to interrupt the fuel pump instead of interupting the ignition as ROW models did with the rotor finger....this prevents flooding and burning the catalyst ...
Leave it there, check it's function.

More read: https://forums.pelicanparts.com/porsche-911-technical-forum/1006866-rev-limiter-83-sc.html
In this thread they talk about a rectangular relay. Porsche switched some time. Don't know. Check if there - beside the blinker/hazard relay which is also rectangular - if there's a second rectangular relay there. If not, then the relay in question is your rev limiter relay.
There might be up to three more rectangular relays behind the gauges:
1. Seat belt warning relay
2. Windshield washer relay
3. Blinker/turn signal/hazard relay

Thomas