2015 Suburban Electrical Power / Reset

[The T]

Hope this is the right place!

2015 Suburban LZ
160,000 miles

Unexplained electrical power loss or too much power drain?

Symptoms:
Driving 60mph with cruise control, use a turn signal to change lanes and the radio touchscreen blinks, cruise control resets
Driving 65 mph at night, turn on the high beam - radio touchscreen blinks, cruise control resets
Occaisionally in a parking lot at low speed (turning into parking spot)- touchscreen blinks, steering becomes very hard
Driving 40mph, trying to raise or lower two back windows at same time - touchscreen blinks
This happens other times, seems like when I make a high power drain request (brakes, high beams, window motors) it takes a few moments for the "generator" to make more power.

What we have tested so far:
Battery tests good (replaced about 18 months ago, tested recently by Autozone and also trusted mechanic)
Charging system tests good at idle (that's what my trusted mechanic tells me)

More information:
Battery isn't dead, so it must be charging?
Although this SUV has all sorts of electrical stuff (seat heaters, dual DVD screens, rear AC unit, etc) we hardly use them, only the front USB port for phone connection, cruise control, and radio/navigation screen. When we actually do use the seat heaters and such it doesn't make things any better or worse.

I'm thinking about pulling out the fuse for the DVD screens (they are always on and we never use them) but I don't think that is the problem.


Is there a voltage regulator somewhere that needs to be replaced? (don't laugh - replace a few of them on my dad's 74 ford LTD back in the day)

Could it be the alternator?

Any suggestions or thoughts are welcome

 

[Joseph Garcia]

I cannot personally help you with your question; however, other members on this Forum that are much more knowledgeable than me will chime in.

 

[Pivot]

Electrical gremlins are a pain - maybe check all the grounds - they are good for creating weird electrical issues. Ground strap, battery, body and chassis. Sometimes the ones on the chassis get gunked up and need to be cleaned and/or replaced altogether. Good fortune finding the issue - post up what you determine it to be!

 

[The T]

Thanks for the suggestions PIVOT!

Based on a hunch I had my mechanic replace the alternator (the part was over $600!!). He had already double checked the battery and the rest of the charging system and his opinion was that something was causing a voltage spike but didn't want to go with the most expensive component first!

Anyhow, it's been almost a week with the new alternator and the problem has NOT appeared! It was happening at least once a day before, so crossing my fingers to hope that fixed the issue.

I'll post again if it comes back, so no news will be good news.

Thanks again to all!

 

[Jackblack15]

Hey all, reopening this thread to see if anyone has found a failure point. 2015 ltz suburban 170k. June 2023 we started experiencing the same issues alternator and battery both tested good , we changed the alternator and fixed all issues. 1 year later same issues are happening the issue seems to stop if we have the rear entertainment and headlights off. About 10k miles ago we installed a magdelete kit and discovered a blown fuse, replaced and blew again a couple weeks ago, the only other thing that that fuse seems to power is the sunroof. Any insights appreciated. Thanks!

 

[Doubeleive]

Hey all, reopening this thread to see if anyone has found a failure point. 2015 ltz suburban 170k. June 2023 we started experiencing the same issues alternator and battery both tested good , we changed the alternator and fixed all issues. 1 year later same issues are happening the issue seems to stop if we have the rear entertainment and headlights off. About 10k miles ago we installed a magdelete kit and discovered a blown fuse, replaced and blew again a couple weeks ago, the only other thing that that fuse seems to power is the sunroof. Any insights appreciated. Thanks!

as noted already check grounds and battery cables. The cables can corrode on the inside and look fine on the outside, you can ohm test them and do a voltage drop test.