Remote Car starter wiring question...

[Chucker]

Hi, 2003 2.5 Baja.
I got a car starter installed several years ago. It worked great for years. I stopped working a couple of years ago and I'm just getting around to trying to figure it out. It's a "Compustar" system.
The door lock/unlock function seems to work fine.
The car starter does not. It "connects" but it just causes (what I've always called) the "solenoid noise." - Not just the "click," but many clicks in quick succession like happens with a low battery in the winter.
(*note - The car starts fine with the key - no issues).

I'm thinking it's just a bad wire connection somewhere. But does anyone have any idea which it might be and where to look for it?

Thank in advance for any thoughts!