Transfer switch not transferring properly

[Alex1995]

Customer had a 100A 240v 20kw generac with an automatic transfer switch. Verified that the voltage was 240v phase to phase, and 120v phase to neutral and phase to ground. The load wasn’t transferring to emergency, so I swapped out the whole ATS. Still not transferring properly. It will transfer to emergency manually, just not automatically. When power is restored, it senses and the generator transfers back to normal automatically and goes into cool down.

Started looking more in depth and saw I was only getting 2.5vdc from the 12vdc terminal(193) to (0) ground. I was also getting 0v from 193 to to transfer(23). Then I shut the breaker off to try and transfer the load, the generator started, and I got the same readings. If I pull the 12vdc wire off of the SACM board, it then reads 12vdc as it should. As soon as I put it back on the SACM board it drops back to 2.5vdc.
Thought there may have been a short in the wires so I toned them all to make sure I had continuity and also separated them to make sure I was getting no continuity on wires unintentionally. Then thought maybe something was wrong with the SACM so I swapped the whole board and it continued to do the same thing. Went to the generator, unplugged every wiring harness and plugged back in to make sure it was in properly, and reterminated the utility sense wires at the generator term blocks. Tried to transfer load and continues to do the same thing. Checked to make sure I had 12v on the battery while the generator was not running, and while it was running.

Im at a loss as of what to do next. Could it be something with the display board where all the wiring harnesses go into? It seems to be working properly.

 

[ATSman]

I'm not that familiar with generac's so bear with me. Am I correct in assuming that the SACM (SA Control Module?) is the ATS motherboard logic control? Sounds like something is dragging down the 12VDC source but you said you swapped the board out so wow, that's a head scratcher!
On all ATS's the 12V gen battery voltage is essential for the start signal sent to the gen start relay. Can you send a pic of the ATS logic schematic or link to it?
Ok just googled it, Smart Air Conditioning Module. A type of load shedding feature. Is this what you replaced?
You may be able to bypass this module if it is trying to load shed on gen start. There should be a pair of output wires you can wire nut and short out.

 

[ATSman]

I'm not that familiar with generac's so bear with me. Am I correct in assuming that the SACM (SA Control Module?) is the ATS motherboard logic control? Sounds like something is dragging down the 12VDC source but you said you swapped the board out so wow, that's a head scratcher!
On all ATS's the 12V gen battery voltage is essential for the start signal sent to the gen start relay. Can you send a pic of the ATS logic schematic or link to it?
Ok just googled it, Smart Air Conditioning Module. A type of load shedding feature. Is this what you replaced?
You may be able to bypass this module if it is trying to load shed on gen start. There should be a pair of output wires you can wire nut and short out.

generac sacm module - Google Search

SORRY FOR THE DUPLICATE