Not saying it is the right solve, but when I did my amp racks I put in 4 cross flow fans. All the amps sit on risers so air can flow across all sides.
Closer pic.
The cover has brushed aluminum grills with a acryllic cover over them on standoffs. I did that so I didn't have to worry about it as I put stuff in that locker and I wanted a constant flow of air.
I wired them through a relay that activates with the remote turn on from the deck and I also wired them through a switch in the stereo panel.I also installed temp sensors on each amp so I can watch their temp if I am so inclined.
To further complicate the process I wired their power line through a thermal switch so that I can set the temp they come on at if I ever feel I need to.
Do I need them? Probably not. But, I did not want to find out later that I should have had them as I plan to only install this amp rack once.
Will it fix your issue? Don't know as it depends on the cause of the issue.
Just thought I would show what I did. I'm not an expert, just someone that does things they way I want to for my peace of mind.