I recently installed a dual Mechman 400 alternator kit in my 2016 Chevy Silverado. The kit came with no wiring diagrams or instructions on the proper way to connect the alternators, but mechman posted a wiring diagram for 2005+ GM trucks online. After following that diagram exactly, I am getting check engine codes for communications between the ECU, PCM, TCM, etc. also losing power steering controls and the transmission will not shift out of first gear.

The kit came with the P101 RVC Bypass Module which I connected and it seems like it didn’t bypass much of anything. The 0 gauge ground wire from my alternators is routed through the RVC sensor along with the 8 gauge wire that Mechman said to not remove.

Does anyone know what might be going on? I’ve been working on this for over 2 months now not being able to drive the truck and Mechman no longer wants to communicate to help fix the issues.

Thanks

 

just ordered one, have they made contact or figure anything out

 

It sounds like you might have a ground issue. Step 2 of the assembly instructions say to "Note: Make sure to reinstall the factory grounding wire with one of the bolts used in this step" You need to make sure that ground wire really is grounded really well or it will cause issues. If that ground wire is fine you need to check all of your other grounds.
https://mechman.com/content/instruct...-LTDB-1418.pdf

Here is a service bulletin regarding issues that can be caused by bad grounds, bad cables, etc. It also lists all of the codes that can be caused by this and U codes (communications) are on the list. Since you didn't list any specific codes you'll have to see if the ones you got are on the list. My suggestion is to do all of the checks listed.
https://static.nhtsa.gov/odi/tsbs/20...68185-9999.pdf

Regarding the P101/P103 RVC delete - looking at the instructions the P101 pigtail plugs into the alternator and then you connect it to an unused fuse location in the fuse block so that it can sense system voltage. I guess there is a P101 pigtail for each alternator. I would connect the pigtails to the same location so that both alternators are getting the exact same voltage signal.

Then the P103 module plugs into the connector for the alternator in the OEM harness - that's to make the PCM happy so that you don't get any codes. So, the PCM "thinks" it is still doing RVC but it isn't since your alternators are sensing voltage directly from the fuse block and the PCM is "out of the loop." It doesn't matter that the ground cable is still going through the RVC current sensor. NOTE that the instructions say "Be aware that your vehicle will no longer inform you of a charging failure."
https://mechman.com/content/instruct...-RVC%20DEL.pdf

The RVC instructions say to follow the general alternator install instructions for everything else. I don't see the 2005+ wiring diagram you mentioned. I haven't installed one of their kits so I don't have any personal experience to share.
https://mechman.com/technical-resour...-instructions/