Battery cranking test

Since we have not solved the OP’s problem yet, I’ll mention one Hail Mary trick we did on my son’t 2010 Silverado. Along the driver’s side fender is a black box containing a huge amount of fuses and electronics. Pull the cover and have a look inside. If it looks like there is a lot of highway grime between the fuses you might consider ordering up a new complex, and yanking out the assembly and replacing it.
 
Many good ideas here that seem to have not worked. Very odd. You might also check the ground straps - make sure they are firmly attached to the frame and clean. The fuse box suggestion is also good but I would try some CRC electrical contact cleaner instead of replacing as a more cost effective approach. Keep us posted and good luck.
 
Can you try with a heavy gauge jumper cable running the starter and measuring the voltage. Try on the positive side and then ground.

Seems obvious you have resistance between the battery and starter.

People have found corrosion under insulation and heat shrink. So looks can be reviewing.

And as others have mentioned a ground strap.

If you cannot get a jumper cable to properly make the connection maybe buy a length of generic battery cable and use that to perform the test.
 
Long story short: 2020 Escalade. Check engine light randomly went on 3x in 2 weeks from different computer systems. Across different systems and so they lead to low voltage at startup being the cause.

The battery SOC and CCA's still showed good, but the cranking test showed ~8.5v minimum during crank which supposedly is well below the 9.6v+ it should be. AI says it's either battery, cable's, or starter is going and pulling way too much power. I have not had any issues with the car starting and it fires up every time. Trusted mechanic friend says cables going bad are common. I replaced the negative cable, the short positive cable going to the distribution fuse box, and the distribution fuse box. The only cable I didn't replace is from the distribution fuse box to the starter b+ terminal. I did check the connections and they look good and I did a votlage drop test on the cable and it checked out good at ~220mV.

I redid a crank test and it showed the same ~8.5v minimum. No check engine lights, but that doesn't mean anything since they would come randomly, give issues, then go away. I ended up replacing the battery as well, and it didn't help the the crank test.

My trusted mechanic friend says I replaced the most important parts and at this point to just drive it and see if it comes back. AI says thats bad advice because the 8.5v low is well below standards and something is still wrong so it's got to be the starter going bad and needs replacement. But I also know AI is wrong all the time, and while that is in fact low, maybe it's normal for power hungry escalades? (Or my consumer grade tester isn't up to par?)

Obviously I can just drive it, but the wife is very hesitant as it has had us stranded before. (the system that threw the code refused to put the car into gear until it fully timed out and reset).

Anyone have any advice
Delete- redundant question
 
Last edited:
Just a small update.

I have been driving it for nearly a week now and all has been well. If it doesn't complain again then it was either the cables, the battery , or combination. Hopefully I won't be back with another update!
 
Back
Top Bottom