Head unit overheating

[fshizle]

Hi all,
Just finished installing a new stereo. Decided to leave the factory headnunit and add 2 amplifiers. One for a 10 inch sub, and the other for the factory speakers. Cause the factory head unit was used, I needed to go through a high to low level converter. After all that, as I went to test it, I found that the head unit overheated straight away, even on low volume. It was only overheating on the left side-the bronze colored bit. It's a mk2 172.
Any help would be much appreciated. Thanks in advance.

 

[glowworm105]

Is that bit not a heatsink? I no on mine there is a heatsink on one side which gets really hot just cant remember which side

 

[fshizle]

Yep it is the heat sink, but Figured out I was wiring it in 2 ohm. Would easily blow the unit if left too long. Thanks anyway.