2004 yukon starter/ignition/wiring issues

[mikemhp]

happy labor day!
my second post in here, thanks for all the previous replies....

little status update-
2004 yukon 2WD, 5.3, SLT 144k miles

had a no crank/no start issue couple weeks ago.
new battery, pulled starter and it tested great, pretty sure it was wiring or electrical related.

i pulled every single fuse to check, turns out the 40A ignition fuse had a tiny crack in the copper circle that i missed on first inspection.... (the little window was dirty on the bottom...)

replaced it and it started up fine for 2 days..

then DEAD BATTERY again. no crank/no start all over again.

NEVER EVEN KNEW I HAD AN AFTERMARKET VIPER ALARM WAY BACK UP INSIDE THE DASH!
never had a remote or any issues in the past- always just used the factory key fob for locking doors and 'beep beep' factory alarm.

so i researched the alarm, it had a valet switch/ignition interrupt function. i pulled the whole brain of it out and started over.

charged battery for 3 hours, checked fuses again, am currently testing it for a parasitic battery drain just in case.

but today after a charge, it fired right up like normal. will check voltage again later this afternoon and in the morning to see if there is any more voltage drop- but if there IS, i am at a loss as to next step........


battery tested at 14V engine on, 12.3 engine off, 12.14 engine off 20 mins later...


fingers crossed, and any insight would be appreciated!!!

 

[Travlinman]

Hope u can figure this out or have someone else reply that has. I have a 03 yukon doing the same thing that started Thursday morning. Wednesday everything was fine, thurs morning click,click,click.
Mine is a 03 yukon with 215.*** on it. I swapped the battery today and did a parasitic draw test on the negative side and didnt show anything so im at a loss.

 

[mikemhp]

update: 8:30 last night batt tested down to 11.7 truck started up fine, but then the batt light in dash stayed on after engine shut off.
checked it half hour later, still on.
pulled negative cable off so as to not drain batt completely again.
still unsure whats going on...

 

[about20ninj45]

Pull the fuse for your radio and cigarette lighter. Check again after 30 mins

 

[mikemhp]

update- tried pulling those fuses, radio stayed on... (it's aftermarket with its own separate positive lead and 250A fuse... wired correctly)
battery was dead again this morning, pulled it out and charged it up to 12.4.
installed it in truck, put the meter on it and immediately it dropped down to 6.1 and kept falling.
pulled it out again, and tested it, read 11.8

obviously i have something sucking juice when it's in the truck, but how to test where that is coming from?????????

 

[mizzouguy]

By radio, i'm assuming you meant amplifier? 250A is huge! If the remote turn on wire for the amp is not wired correctly, and the amp never shuts off, it would drain the battery like that.

 

[mikemhp]

i did a further test on the alternator.... thinking that is what is bad.
disconnected the alt, hooked up the battery, and charging battery again now.
but first time i tested it in that setup, no voltage drop from battery.

the stereo/amp setup looks like it is wired better than the rest of the truck.. never had an issue with any of it, but i will check the remote turn on just in case...

3 amps, 2 crossovers, 1 equalizer, separate power and wiring, 12 speakers, but i have a little experience with car audio, and the setup looks better than i have ever seen before. (truck came with the system, i did not install it, but it looks very professional.)

leaning towards bad alternator now that i disconnected it, and truck started right up with full charge on battery, then died 4 minutes later.

 

[mikemhp]

i did a further test on the alternator.... thinking that is what is bad.
disconnected the alt, hooked up the battery, and charging battery again now.
but first time i tested it in that setup, no voltage drop from battery.

the stereo/amp setup looks like it is wired better than the rest of the truck.. never had an issue with any of it, but i will check the remote turn on just in case...

3 amps, 2 crossovers, 1 equalizer, separate power and wiring, 12 speakers, but i have a little experience with car audio, and the setup looks better than i have ever seen before. (truck came with the system, i did not install it, but it looks very professional.)

leaning towards bad alternator now that i disconnected it, and truck started right up with full charge on battery, then died 4 minutes later.

View attachment 182728 View attachment 182729

 

[mikemhp]

yep... alternator.

battery has been charging 2 hours, reads 11.9v, alt disconnected, started right up with no drain on voltage.
all accessories came on like normal.

plan now is to pull alternator and swap out for new one, FULLY CHARGE the battery, and fingers crossed, problem solved.

dashboard battery light is still on, however............ thinking that is just computer telling me what i already know- that battery is not charging.

 

[mizzouguy]

seems like you are on the right track

 

[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