Electrical plague 12volt system, alternating current leakage?

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BG1988

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still having a bit of an issue with the 12volt system
I was only getting 14.3 at the tap it was causing the transmission not to move in drive (also shuttering if it worked ) (worked in M4).. other wise it would sit there (you can revv up your engines)


i did resit the connections and tighten the crimps as they were coming apart again..

(i bought new cables just not put in yet) as i think the battery is moving around causing the crimps to come apart..

anyways after doing that everything is close to what it should be 14.9v is the actual factory cold start voltage preset..


it was jumping around from 14.6 to 14.8 at about 60Hz ripple (you can see the OBD reader reading rapidly refreshing and moving all over the place)


but everything seems to work now it does shutter slightly.. on cold start only (only does it once)


the SUV shifts smoothly now,, threw out the gears.. before it was playing dead in drive gear (and no autostop)


the engine idle is in sync with the voltage ripple so the engine idle has a ripple as well to go with it... it also has the funky rhythmic idle to go with it
 
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BG1988

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Where did you throw the gears out to?

2001 Yukon SLT
2012 Yukon Denali XL
2011 Yukon Denali RIP 5/20/18
haha should have been thru out the 4 gear(s), and/or sun,planetary gear sets
 
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BG1988

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Yeah the cables were pretty dirty under the positive cable

the voltage is quite a bit more stable at 14.835 to 14.865 volts

instead of jumping around from 14.2 to 14.8 aka "heavy ripple"

the idle still has the normal rhythm idle but doe snot bother me because AUTO STOP is working correctly now SO i don't have to feel it anymore.

but I don't have any reason to believe it has an issue with misfires as the catalytic converter temperature Stays at a stable 350 Celsius or 662 Fahrenheit when idle.. other wise it would be much much higher

20200314_115323.jpg
 

dnt1010

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Just got a new battery for mine. The ACDelco was 6 years and 4 months old so actually gave pretty good service. It had been pulled down completely dead recently and I think that did it in. Went with an Advance auto parts 760 CCA AGM battery (their store brand) it fit perfectly.
166 bones tax and all with a 255 fathers days discount and turning in the core. Ole ** is ready to roll again....
reason that I mention this is that I was having some odd "episodes" when the old battery was getting really bad. takeoff hesitation/wierd code somethign about brake switch communication and of course it finally would not start one morning after a couple of weeks fo the odd BS going on. TaDa all good now with the new battery it drives like new again.
 
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BG1988

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Just got a new battery for mine. The ACDelco was 6 years and 4 months old so actually gave pretty good service. It had been pulled down completely dead recently and I think that did it in. Went with an Advance auto parts 760 CCA AGM battery (their store brand) it fit perfectly.
166 bones tax and all with a 255 fathers days discount and turning in the core. Ole ** is ready to roll again....
reason that I mention this is that I was having some odd "episodes" when the old battery was getting really bad. takeoff hesitation/wierd code somethign about brake switch communication and of course it finally would not start one morning after a couple of weeks fo the odd BS going on. TaDa all good now with the new battery it drives like new again.
I think if there is any further issues i would change the air filter often as well seems a dirty air filter can cause a bunch of issues
seems like the transmission is acting funny(shutter in first gear) that would be the first thing to look at.
 

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