wiring issues with coil side and tci

Hi folks,

I've owned my 88 Caddy for a year now after spending time gathering part and getting it past the MOT i tried celebrating with a new radio. i knew a previous owner had messed with the wiring in the past just by some of the crazy stuff coming into the cab, never realised the extent of it until removing the dash cluster and every wire has a crimp as they had just snipped off the old one. so after wiring up my speakers and radio it wont start. I'm getting no voltage at the HALL sender or the tci.

while i was having a nosey I peeled back some tape and a yellow relay fell out as it was poorly crimped. one wire with a link wire coming from the coil, one going to a single pin on a coolant sensor that isn't there and one wire going to the bottom of the carb.

could anyone be so kind as to tell me which wiring diagram I need to read (there's that many in the haynes manual I don't know where to start) or suggest what to do.

literally any advise would be much appreciated, cheers in advance.

The ignition system is pretty simple. Battery, ignition key to coil  via Tci to distributor. Sound life a bad contact low tension side. Just had a loose tci connector issue. Check for a spark from lead from  coil to dizzy. I'll send testing link next

Mk1 Golf Ignition Testing - YouTube