UK Car Repair Questions? Ask a Mechanic for Answers ASAP
Can you check the earth lead on the gearbox is connected correctly and that you havent trapped the wiring as you put the gearbox back.
When you tried a jump start did it crank over.
If not disconnect, lead to starter motor and see if that makes a difference to the battery.
There are a lot of wires around the battery area are they all tight and fitted correctly as they are disturbed when doing the clutch.
You will have to disconnect starter motor leads and see if this changes dash lights
Im still thinking a wire is trapped somewhere causing it to earth back through car
starter related,with it disconnected you could tow the vehicle see if it starts then.
Please keep me informed
You said the lights got brighter when starter cable removed.
Did it start with a tow
Make sure the cable you removed dosent touch anywhere.
Please check for trapped cable somewhere again