Larry Huffstutler

My 2015 Silverado WT had the harness from S48A to X61A but was not connected to X50A. I installed a 6 relay fuse/relay box outside the firewall just above the Upfitter passthrough boot and tied the wires into X61A, X1. I wired the relays for ground trigger. The Upfitter switch I got has TC, Cargo Light, CNG, and 4 AUX switches. I used the CNG switch for my air bag compressor by using an ESP32 to make the CNG relay latching. The CNG switch uses the exhaust brake pin in S48A, X2. I am pulling power from X61A, X7. So here's my problem, if I tie into Battery Positive Voltage (15 amp) everything works fine, but if I use Accessory Voltage (10 amp) or Run/Crank Ignition 1 Voltage (15 amp) nothing works and the indicator lights show 3 of the aux switches on. All are switched off. These lights come on when a door is opened as well. Again everything works as it should with it tied to Battery Positive Voltage at X61A, X7. Any thoughts? Okay, I found a blown fuse which fixed part of the problem. I still have the indicators coming on on aux1, 3, and 4 but not aux2. This happens when I open the door and goes off when I turn on the ignition. From what I see in the wiring diagram why are they not all on?

I bought my 2015 Silverado 1500 with a CNG conversion already installed which was cool because I figured I could save a lot on fuel. Now that CNG cost more than gasoline where I live and I need the bed space i am removing it. It kind of sucks because I can drive 40 miles into Oklahoma and get CNG for 99 cents a GGE. I removed the tank, regulator and hoses but the wiring is causing me a problem. Down near the anti-lock brake system on the frame there is a connector that goes into the CNG harness. I don't see a factory harness to plug back in. With this connector disconnected the truck will barely run and stinks way worse than me. Reconnecting it fixes the problem but I have already ruined the catalytic converters. Does anyone have experience with removing one of these kits or know where the original connector may be located?

Thanks for the response. Cat is what I figured but would a bad cat cause the temperature not to change? It seems that there is some flow through the converter or I would have some drivability problems. Any flow at all and the temperature ought to change some. I wouldn't think I would have good O2 readings if the converter was really bad. Where does the temperature reading for the cat actually come from?

My 2015 Silverado 1500 5.3l has a converter on the passenger side that sits at 432 F and does not increase while running. The driver side cat reaches well over 1000 to 1500F. I got the dreaded P0430 code and it looks like most say to replace the converter. I did replace the downstream O2 sensor thinking that is where the control module was getting the temperature but it made no difference. The sensors on both banks read about the same O2 levels with the front sensors a little higher than the backs. Any ideas other than a wiring problem? Thanks