Electrical Issue

Hi, so i currently have a few things thats are happening haha:

1. I currently have no indicators or hazzards, relay makes a constant buzzing sound, i have replaced this relay and still the same issue.
2. I also have this i also have a weird problem where selecting reverse gear causes my battery light to come on and the temp and fuel gauge stop working. This also happened when i was stuck in bad traffic.
3. If i use my horn/ hazzards it causes my stereo to cut out.

The hazzards, horn and stereo all went at the same time, but the indicators have worked perfectly for months and now they have also gone. Not sure if i have one issue here because ive checked a manual and i know a lot of these are controlled by one of the ignition relays or if i have several, but ive had both the battery and the alternator tested, and they were both fine. Cheers in advance!
Sounds like a water ingress/corrosion problem in one of the main wiring loom multi plugs..........
Cheers mate i had the dash out the other day and checked all the grounds and the plugs, All the pins look like their brand new so im at a loss haha. Do you know if there are any other grounding points in the boot for the rear light clusters? Im gonna try and have a check tomorrow see if i find anything.
Flasher unit under the steering column might explain the indicators problems. Little black box and it has white writing on it
Cheers mate i've replaced that and tried 2 new ones still nothing sadly. I can hear the relay trying to make the clicking noise but then it just starts to make a buzzing noise until i turn them off haha.
Right sorry its been a while but i've tried the flasher unit and nothing, checked all the earths i can find on the car and things seem fine. I'm gonna go over everything with a amp meter tomorrow. But the other day the car cut out on me on the way home from work, I've checked the ignition system and changed the plugs (old ones were knackered). Now the car starts fine when cold but when the car warms up and the revs drop the car is cutting out. Any ideas if this could be linked to the electrical issues i have been having or if there is anything worth checking on the carb?
Cheers in advance.