2004 yukon starter/ignition/wiring issues

[mikemhp]

if i disconnect alternator and check voltage should i be seeing any kind of drop with the engine off?
looking to determine if alternator is bad before i take it out and go have it tested; buy a new one

 

[mikemhp]

alternator tested good at o'reily's
saw another video to test for bad alternator diode... w/engine running, put the meter on 200Vac to check for ac volts. read 31.0...... think it should be reading zero

is that an indicator of a bad alternator diode even though it tested good at the shop?
not sure if that check was part of their test....

HELP!!!!!! before i drop money into a new alternator that i may or may not need

 

[mikemhp]

new alternator, same issue. something is drawing 31vac from the battery with engine on

 

[mikemhp]

now i'm getting a drop in voltage from the 2nd new battery even with negative cable disconnected!!!!
wtf?????

update- voltage drop went away.... think i just needed to let the computer go back to sleep.

still having batt drain issues after starting it up then shutting it off...

have checked everything!!! disconnected fuses at all accessories: A/C, radio, ABS light (which is always on with truck running, btw) alternator power cable, ......... still can watch the volt meter go down when engine shuts off

help!!!

 

[mikemhp]

update- swapped starter and park lmp relays. solved batt drain problem.
truck starts right up now, but with key off, batt light on dash stays on.

in addition, when i turn key off, it used to open the door locks after engine turns off. that is no longer happening.
would replacing all the relays be a good thing to do?

 

[mikemhp]

saw a video regarding a ground wire that goes to the rear of the engine block and suggested to un bolt that and splice a new one over to the braided ground wire on the upper side of the firewall (engine compartment)...
question is- on my truck, that wire isn't bolted... just hard-wired to the block..
suggestions???? should i try that?

replaced all the relays in fusebox, took the truck out for an hour or so with no problems...
but the battery light on dash still stays on after key is out engine off...
worried about batt draining overnight still.

 

[06Escalade]

Maybe I missed it but have you removed the radio and whatever else electronic that was modded into the harness for a few days of tests?

 

[mikemhp]

yes...
still starts up in morning, batt not draining as much anymore with everything re-connected after replacing all relays at fuse box under the hood... however, batt light on dash is still lit up.
very slow batt drain with engine off, but starts up strong every day since that latest fix. still issues with key off not unlocking power door locks anymore like it used to do, but that's a new and small issue

ill give it a couple more days like this and double check voltage/amp draw/etc..

thanks!

 

[mikemhp]

performed parasitic drain test and pulled fuses one at a time.. here are the suspects:
ALL TESTS PERFORMED WITH METER SET AT 10A ON THE DC AMP SETTING....
PCM B (20A) WENT FROM -1.57 TO -1.22
IPC/DIC (10A) -1.57 TO -1.20
TBC BATT (10A) -1.57 TO -1.39
IGN A (40A) -1.57 TO -0.3, THEN TO ZERO

first 3 are slight drops, but the big one is that last one, IGN A....
how do i find out what that one controls?????

help!!!!

 

[Danny3737]

I wonder if there is a chance, that it’s the ignition switch