A whole lota yellow lights on.....

[Hoefler]

I have one, if you are close to SW Mo. Most auto parts store can do in vehicle testing.

 

[Grumpy8811]

I used to tell the mechanics at the shop all oddball electrical complaint troubleshooting should start with the batteries..

 

[BigPapa]

Unhook ground from one battery, put your voltmeter on the other and get someone to crank it. See how far the voltage drops. Hook that ground back up, remove the other ground, and test the other one.

 

[Topzide]

I picked this one up a while back, and so far I'm pleased with it.
https://www.harborfreight.com/12v-digital-battery-and-system-tester-58759.html
Didn't break the bank and has been very close to other types of the testers on the market. (checked a battery for friend, took to auto parts store to check and was told same thing)

 

[bcbender]

UPDATE:

Tested batteries with a handheld unit a friend had... both check out OK with one resting at 12.84V and the other 12.85V.. Internal resistance was 3 Mohm and almost same on both. Funny thing when I put it all back together and started it.. no warning lights came on!! Was able to cycle through 4wd and everything other than the MIL was off... Then tried again (restart / reboot) and everything back on.... So re-disconnected the batteries in the same sequence I did when testing them (unhook one, test, then reconnect and test other....) and all warning lights back on... Discusseted with it, I had a beverage or two and tried again.. no dice.

Fast Fwd to this am.. Decided to try one more time before calling dealer... and started truck. No waring lights!! decided to drive to work today to see how stable it is.. 2 mi down the road everything back on.. then stopped and turned onto the interstate.. everything back off... Got to my exit.. bang everything back lit up!... So now it seems like maybe a bad connection somewhere?? Or the speed sensor is intermittently working? I have MaxCare so no problem there, my only fear is I take it in and they can't duplicate it.....

Gonna call them this am and make an appt, I'll keep you posted

 

[BigPapa]

Most DTC's require at least two failures to activate a CEL.

 

[Ozymandias]

Just don't delete any DTCs, leave them all alone. So they have the information to start with.
Even with the lights frequently out, the fault are stored and accessible with WiTech.

 

[Diesel85]

Just don't delete any DTCs, leave them all alone. So they have the information to start with.
Even with the lights frequently out, the fault are stored and accessible with WiTech.

Yes -- Don't delete the codes!

Right on @Ozymandias

 

[bcbender]

Truck going in Thursday, will Alpha-OBD pull all the codes that are present prior to me taking it in (w/o the security bypass cable)? I have the cable but dont want to install prior to a warranty service.. First time truck going in, I want to have a record of what is there now... Also based on Topzide's post, I do have a code for low DEF as I had the de-rate screen on when the other codes came up (I knew it was low as I ran it down so I could fill with fresh from the summer...) Now after 6 or 7 drives not sure what's there, but the DEF is full since a month ago when all this went down.

 

[Diesel85]

Yes, AlfaOBD will read all codes without the SBC.

 

[bcbender]

UPDATE:

Sorry have been out on business but wanted to circle back and close this one out. Dealer had the truck for 2 weeks, swapped out the wheel sensor (no improvement).. They found it to be a cut / chaffed wire on the LR wheel sensor circuit that was shorting to ground. This is where it got interesting......

They claimed that MaxCare would not cover the repair since the damage to the harness was caused by interference with the B&W hitch release lever and the harness... I then retorted that the truck was purchased with the hitch promoted, sold and installed by the dealer when new and as far as I was concerned it was part of the truck and not my issue... ( this was during COVID so my hometown dealer did not have any trucks anyway)

I did not wish to pay the dealer labor to remove the bed and replace the harness and they recommended to repair the damaged wire as another option. I opted for that path and took the truck back to my shop for the repair as it was not my intention to pay the labor involved in it.

This is my local home town dealer and I'd surely recommend them if you need repair in central NC, they did not charge me for the diagnosis (I'm certain it was good willed), however I was impressed that they were able to actually diagnose the issue as it could've been weeks depending on the tech's capability. They area that was damaged was not visible, not easy to find, and certainly not easy to repair. I have since re-insulated and relocated the harness to eliminate the potential for contact moving forward.

I will continue to use this dealer for warranty repairs (if needed) full disclosure, they told me I could ask the selling dealer to repair it but that I think would be another can of worms... Its fixed for now and Im ok with that...

 

[Signal73]

I recently installed a B&W and the instructions even mention to relocate the harness so it does not chafe the wire harness it passes by.

 

[bcbender]

I recently installed a B&W and the instructions even mention to relocate the harness so it does not chafe the wire harness it passes by.

Clearly my selling dealer (experts) did not care to take that advise......