Hutchy

Have you confirmed proper ground?

I ended up splicing one of the old sensors, because the dealerships are closed on weekends. Although this got the truck out of limp mode, it still has a “service brake system “ error. As a side note, before splicing it, there was no power brakes?

I was doing full brake and rotor replacement on my ‘19 GMC At4 and the front brake sensor pigtail was troublesome; the wires ended up snapping off in the pigtail.. now the truck is in limp mode. If someone can tell me how to de-pin this thing, I can solder new wires OR if there’s a bypass hack that would be good too.. Would connecting the two wires work?

Found it. Turns out the lead power wire wasn't making a proper connection; I'm assuming it wasn't seated when I inserted it into the connector and must have pushed it out just enough to look like it was plugged in, but not making contact... Thanks for taking the time to respond to the thread. Cheers,

ya, I'll try chasing it down again today. The truck is always on Acc, because I believe the kit was designed to energize upon ignition source.. But if that lead from the battery is the primary source and there's no other ancillary circuit; I can't help to wonder what those wires are for, that connect into the main harness.. I'll update later

I replied a while ago, using my mobile, but evidently did not go through; so ignore any duplicate responses, please. Thank you for supplying those links. I did, however, referred to them just prior to installing the kit. The OEM kit was a complete kit and included the battery terminals, bus bars and fuse. There is confirmed power across the fuse in the battery compartment; it's just not present at the auxiliary fuse box. That's why I'm assuming there is some sort of other primary fuse that may be missing somewhere in the circuit; like a feedback loop to energize the relays?

Hi Everybody, I recently purchased and installed the OEM upfitter switch kit, to my 2019 GMC Sierra AT4; looks nice and clean. Anyway, I'm about to connect a device, but realized there's no pwer going to the (kit supplied) under-dash auxillary fuse/relay box? The switch do illuminate, but there's no power coming out of the leads. I'm assuming that I need to install some primary fuses, because my truck didn't originally come with the 9L7 option? I've COMBED the internet and can't really find where the main power junction is located. There was a diagram that said Fuse #94 should be one of the inputs, but the under hood distribution box only lists up to #92; with none of them being identified as related to these upfitter/auxillary switches? Hopefully someone can help out.. Thanks in advance,

I recently installed the OEM kit and found it was fairly easy, although quite a lot of steps. However, now that I'm at the point where I want to connect something to a switch, I found there is no power going to the under dash auxillary distribution box; although the backlights of the switches do illuminate. It’s quite the chore to acquire a schematic or electrical diagram, to locate the power supply to the power box; because my truck did not originally come with the 9L7 option, I assume I need to install some primary fuses?