I'm tracking down an electrical problem that is preventing my a/c clutch from engaging on my "new" used 2001 3500. Van was converted to a high top minibus when new with some add on relays installed behind glovebox. One of those relays (not sure yet what it switches) clicks when I turn the a/c on and clicks again about half a second later which 2 clicks are repeated over and over at about 10 second intervals and the relay gets hot to the touch. The relay is good (swapped) and freon level right. The blower comes on but air not cool. Below the van frame an aftermarket double refrigerant cooler fan comes on (or at least 1 of the 2 fans does) and stays on when a/c turnedd on. The a/c clutch never engages (never gets power). This problem will disappear (cold air) for a few days and then come back for a few days.


I understand relay is basics but don't know what the quick "on/off pause repeat" indicates.
I have come up with the following "theory";
The low (trigger) circuitry OR more likely the high (load) circuitry has a short, overload or bad ground and the relay (HG 4185 (C-1Z) 12V 40A) may or may not have some kind of thermal or overload protection. I'm using terms I'm only slightly familiar with and would appreciate any guidance as to what condition would make a relay act like this- Fl. is starting to get real hot.

Thanks