Current reversed on compressor spike controller

[sciguy125]

Originally Posted by mechanicalbrain

The spike is literally not receiving a signal.

If you haven't already tried another spike, do so. But, we had this problem too. It took us days to figure out. You're probably not putting the PWM connector in right. It might go all the way in, but the pins might not actually be in the connector. Sometimes, we would even get only one or two of the pins in.

Just to make sure though, pull the connector out of the spike. Test it for voltage between ground and the appropriate signal pin. It should be a solid 5V. If you have that right, then I probably found your problem.

Actually, I just reread your post...

Originally Posted by mechanicalbrain

we got a response from the compressor but all that happened is the fan made a twitch (I'm guessing the motor switched polarity) once every second

Do the voltage test still to check your code. But also pay attention to the LED once you plug it back in. Orange is off, red is reverse, green is forward. I also think that the spike makes a clicking noise when it changes direction (I can't remember). You might also want to put in a meter instead of the compressor to make sure that it's getting a solid 12V.