Solder substitute please?

need to join some car electrical wires(from immobiliser, back to original,(non immobiliser) state. im just curious is there a product that i can use as a substitute for solder, bcoz these wires are only the small "thread like" wires,and im not that good at soldering small things, is there any adhesives etc....bty im not stealing cars, my immob fckd up, and i want to take my car back to, factory, non immobiliser, this crap that got installed aftermarket....b4 telling me i cant immobilise my immobiliser...i did, i just need some way of permantly joining these wires safely