Remote Start/AC/Head unit issue
 

I had a local shop here install a remote start module and it worked perfect for almost 6 months.

Two months ago I received my Sony XAV-AX100 head unit and immediately after installation the remote start still worked but for a short period of time. It could be 30 seconds or 10 minutes and almost never the full 15 minutes it's supposed to stay on. It's not the remote start module that turns it off because if it did it would have turn off the lights. Another symptom that occurs only when I remote start is the AC compressor not turning on. This only happens with the remote start.

Using the key to turn it on works no problem. The car drives normally as it always have, stereo works fine, AC works and blows cold but the damn thing won't remote start and when it does it's probably blowing hot air and not even cooling the car which is the main reason I installed it.

I went back to the installer a couple of times and he couldn't figure it out saying it was working without the Head unit so he couldn't do anything about it.

I checked all the relays and swapped them around and they're working properly. The only thing different between the stock head unit and the Sony is that it doesn't use the D12 connector which has the VSS (speed sensor), SNS2 (grounded), and a few other wires. The pin out picture shows that connector but I actually only have a few of those wires and not all. Is there something there that could cause this issue?https://uploads.tapatalk-cdn.com/201...c52115b5e4.jpg

Sent from my Pixel XL using Tapatalk

Usually for a remote starter you need to connect +12V to the starter and the ACC, which is the power for the blower and radio etc. For the specific starter I used (on a Honda CRV), you needed to add an extra relay to power on the extra ACC wire to the module. Since you installed the new radio, a possibility could be that it is providing some kind of feedback voltage / ground loop and the module is cutting out the power and turning the car off.

Not sure how the shop wired the module but I'm pretty sure it is always on so it can detect the remote start signal and turn the car on.

I know there are two 12v signals going into the headunit one is always on even with the car off and the second turns on with the key in ACC.

I'm thinking of adding a relay on the ACC wire that switches on and uses the always all signal to power the headunit instead of the ACC directly like the picture below.

Is there an easier way to prevent the headunit from sending feedback other than a relay? Maybe a diode?https://uploads.tapatalk-cdn.com/201...048fc83289.jpg

Sent from my Pixel XL using Tapatalk

Relay would be the easiest option. You could also try the 1N4001 diode but then you have to make sure you get the proper rating