relay wiring replacing with a thin wire

I have a Bmw e36,1994 and my sunroof stopped working when i pressed the switch nothing happens.I discovered the cause it was a relay located under dash a SPST relay.terminal 30= 12+volt alltime 5mm diameter wire,terminal 87= to sunroof switch 2mm diameter wire,coil-terminal 85 =12+volt 5mm diameter,terminal 86= ground, a thin wire from ZKE(-central unit of car).The fault-the ground was dead from ZKE no output to terminal 86 to close relay.Since i did not found the fault,and no ground switched trough ignition(i want sunroof to work only with ignition on),i cut 85,86 terminal wires and i put terminal 86 to ground alltime,and 85terminal to a 12+ switched trough ignitio.I used for 85 terminal a 12+ v signal from accesory a thin wire about 1mm diameter.  Is that a problem,because as i mentionedthe original 85terminal had a 12+v wire wich was about 5mm diameter?COuld i burn something like accesory wire?

This is going to get involved but there is no way 85 would be 5mm, that's the US 8 gauge with 100 + amps capacity!  The relay should read 87, perm 12v+, 85 to ground, thin brown, 86 to ignition and 30 to swtch. To make this work off igniton simply join  the wires at 87 and 30.