2019 yukon xl No Start

[T_Brad]

2019 yukon xl 5.3. Problem started with the occasional no start when starter button was pressed. Then it would work on the second try. Over the next two weeks it would happen more often, until we got to a point where it would not start at all. (Vid 1)
- battery tested all good.
- replaced starter. This did nothing.
- starter relay appears to be fine (See vid 2)
- starter fuse is good
- ecu module is tight and seated well. (I have not pulled it to look for corrosion or wire problems beneath it

When i try to start I get a single click. (See vid 3) Single click when trying remote start, and single click when trying to jump at starter relay (See vid 4)

Can someone help me on what my next test should be, or point me in the right direction with a similar problem they solved? Thank you in advance.

 

[Joseph Garcia]

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics of the truck, please.

I can give you some initial pointers, but other members of this Forum much more knowledgeable than me in this area will chime in.

You say that the battery tested good. Did you have it load tested on a bench with an actual load tester unit?

Check the Ohm resistance of the battery cables. They often look good on the outside, but are corroded on the inside, but an Ohm test should determine the condition of the cables.

 

[blondie70]

Mine did about the same thing and I found the ends of the battery cables (that attach to the battery) were kinda glazed . I used a pocket knife and a battery terminal brush to clean them up. Worked ok then. Good Luck

 

[Fless]

I would suggest a voltage drop test to confirm main cable integrity and capacity to handle a load:

 

[T_Brad]

Thanks again for the replies. So I am an idiot and realized when I was jumping at the fuse block I was on the run/crank relay, not the starter relay. Picked up a multimeter and started testing all things battery related. Grounds, Bus, etc. I have no power to post 30 of the starter relay. So I am down to the Nuetral Safety Switch, Anti-theft, or a bad contact for battery power or ground at the fuse block. Before I get into removing all the cable protection would anyone have a wiring schematic.

Also some additional info I should have stated in my original post. No corrosion on anything. Engine compartment is really clean. A shade over 70K miles.

Am I missing anything else I should be testing.