Long story short

Bought a 56 Hawkeye (non turbo) in January
Drives greatClean car inside and outHad no issues.

Went to wire some neons in today and found a small cable not connected (I'll attach a photo) anyways when I connected it up an engine management light appeared and started flashing when engine running.

So I turned it off and left it on ACC and the engine bay starts making mad noises I'll link a YouTube video. (https://youtube.com/shorts/dZy9TdvXNEM?feature=share)

Then I noticed the radiator fans start spinning only in ACC with that new found cable plugged in.

So
I disconnected the new cable and the radiator fans stop and the engine management light goes off.

So in summary

New cable in & engine turning =
Engine management light flashingRadiator fan NOT spinning
New cable in & ACC on =
Engine management light on solidRadiator fan spinning
New cable unplugged (as I bought car) & engine on=
no engine management
No radiator spinning
New cable unplugged (as I bought car) & ACC on=
Solid engine light (which I think is normal start up)
Radiator fan not spinning
Anyone got any ideas on what's going off? Taking it to my mates garage Monday but I'm just sat here now worrying the worst incase there's something desperately wrong with the car! I've drove it 8 months already so I wanna stop driving it now till I can get this resolved as I don't wanna **** the engine.

 

They're supposed to be disconnected they're the test connectors disconnect them and leave them disconnected

 

You sir, have made my day!

I was so stressed with it being a new ish purchase I didn't want it being a lemon haha.

Thank you so so much you've made my weekend.