You need to look at your wiring diagrams.
The compressors use a huge ammount of power.
When ever I've done my installs I run a 0awg cable from the battery to a split terminal. Fused to about 60/8/amp. Then another feed from the iggnition
I run relays off these so the relay can be individually fused and take the brunt of the power. Not the cars harness and components.
If your not sure give it to some one who can, or it's a fire waiting to happen imo