GEN5 Customers please EMAIL for Authorization BEFORE shipping any Gen 5 Harness

After building over two thousand Gen 5 harnesses since 2016 we've learned the hard way what a few of the failure modes on the other end can be.  If you want this to be a good experience for you and/or your crew please understand the following details:

  • Every Gen 5 LT harness especially those with crash damage, missing sections or pieces must get authorization from us prior to shipping.
  • If you do not own a scan tool with live data capability you will need to purchase one and learn to use it prior to starting your engine for the first time.  Any and all tech support starts with us asking for codes and live data values.
  • We no longer support engines with a cam change.  These ECM's are extremely sensitive.   Mail-order "Tooners" are a recipe for failure and the best local LS tuner can really botch a Gen5 tune.  Finding a local tuner who is competent with Gen 5 remains hit or miss at best.  As a result, we work only with Speartech which tunes stock engines with a stock cam profile.
  • Mix and Match "Frankenmotor" setups are not supported.  If your takeout is not complete and stock L83/86 or LT1 configuration from a single vehicle we are unable to support your project.  See the videos for the possible mix-match failures.  We do not support mix-and-match compatibility in any way.
  • We do not support any Gen 5 Silverado or Sierra (L82/84/87 or L8T) donor configuration after 2018.  Exceptions are the LT1 from a Camaro through 2023 and Fullsize SUVs such as Suburban, Tahoe and Escalade through 2020 which have the E92 ECM.  It is up to you to confirm your donor has an E92 or E92A ECM before sending a harness to us.
  • Note that 8 and 10 speed transmissions must be an exact match to the year of your harness, ECM and TCM.  There are differences in the valve body and harness after 2018 and the wrong combo will fry your transmission in short order.  It is up to you to confirm your components match yourself by watching the videos on the FAQ tab.

What to Send for Gen 5 LTx?

Duramax Harness Shipping Instructions:

How to ship and what happens next?

What to Send for Duramax?


a message. (Responses are Monday-friday usually within 6 hours)

About  Ken Wolkens

Please remove everything that can be disconnected before shipping any harness for conversion.

  ECMs, TCM's, Modules, Sensors, Pedals and extra sections like the Duramax Accelerator Pedal Jumper or the Transfer Case Jumpers should not be sent.  Battery cables should also be removed if you plan to reuse.  Any extra items will be cut off and disposed.  We do not retain, stock or sell replacements of any of these items.  If you think you might want it pull it off and keep it on your end.  Finally be sure to write your name, EMAIL ADDRESS and telephone number on a piece of paper and place it inside the box so we can EMAIL you after your harness has been tagged, cleaned, peeled and inspected.  We will schedule your completion date and Invoice via EMAIL 3-4 business days after your harness arrives.  Payment of our invoice is simple and easy with any credit card or a Paypal account when the work order is completed.

                                                                                                Thanks, Ken

Duramax Harness shipping info:


7777 N. WICKHAM RD.  

​SUITE # 12-122

Melbourne, FL. 32940 US

As an engineer, I've worked on numerous GM vehicle powertrain programs when I lived in the Detroit area AKA The Motor City. As a result, I know these harnesses inside and out.

I am professional and punctual. If I say that it will be done or I will be there at a certain time you can set a watch by me. I have built over 4200 harnesses since my career began in 1994 and have numerous references and high-profile customers who will be happy to talk about the high-quality work I have done on their Stand Alone Harnesses.

Email questions can be sent here:

Normal Business Hours are 8AM-6PM Mon-Thurs and 8AM-2PM on Friday. (Eastern Time Zone)

We are closed Saturdays, Sundays and Holidays.

Due to labor availability constraints and to streamline efficiency, Email is our primary means of communication.  We check and respond to email multiple times daily.  If you have checked all of the website tabs including scrolling down and your question is not answered in our Q&A formats, in the Statement of Work, or in one of the 50 or so videos on the site a telephone appointment can be set up via email request.  You must detail the reason for the call in your email and we can set a time/date for a conversation.  Questions that are already answered on the website will be directed back to the site.