I have a Braineack MS3X set up as a NA Miata in my 73 Ford Courier. A/C was working ok but the evaporator was freezing up do to running a trinary switch on the high side. I swapped to a low side cycling switch to prevent that and now the MS3X is not reading Datalog signal to ground. I touched nothing inside the car so I don't see how swapping switches under the hood can cause my problem. I have a tablet dash running a full version of Tuner Studio so when I flip the A/C switch the "A/C" light should come on immediately like it was doing before. It no longer does. If I leave the A/C button on while running it will sporadically show A/C is on after a few minutes and pulse the compressor relay off and on really fast. I've tested the wiring in and out of the MS3X and it all seems like its working properly. Pin 30(datalog) is open until the A/C is switched on then has 2.2 Ohms to ground. I installed a jumper wire straight from the DB37 to ground also and got no change. I can switch on INJ H in the MS3X test mode and activates the compressor relay normally. attached is a datalog I took while it was freaking out.

 

here's my tune file in case I accidentally messed something up

 

UPDATE- I let it sit over night out of frustration and had the idea to change the A/C input from Datalog to Launch-in to make sure the problem is in the Datalog circuit. The A/C light came on like normal and worked when i pushed in the clutch. I switched the input back to Datalog to make sure the problem is on the Datalog circuit and that's back to working normally. I am really happy its back working but pretty frustrated and confused and would like any input on how I could go about tracing the cause of the problem next time it happens.