Another Parasitic draw test question. Is it possible to test with a multi meter while keeping power to the vehicle?

c good

Active Member
Original poster
Dec 8, 2011
416
I'm trying to avoid disconnecting power to the Envoy altogether so no actuators go bad. Is there a way I can hook up another battery, or use the 12v socket in the dash to keep power to the vitals while testing for parasitic draw? I'm aware of the hook on multi meters, and am willing to purchase one...... but are they sensitive enough to check for parasitic draw with any accuracy?
 

mrrsm

Lifetime VIP Donor
Oct 22, 2015
5,984
Tampa Bay Area
Best Practices and Tools Required for The Passive Detection of LOW Amperage Parasitic Draw:



GMT Nation's Tutorial on Parasitic Draw:


All In One Digital AMP Clamp and Meter with TRUE 6000 RMS and 1 mA Detection Sensitivity for under $50.00

(ALWAYS ...READ MOST of the Buyer Comments FIRST):

GOODCLAMPFORPARASITICDRAINTEST.jpg


71BzGxJ7ZmL._SL1500_.jpg

 
Last edited:
Jul 6, 2014
9,237
I've used a set of jumper cables on the block and the positive that goes to the fuse block from the battery in a pinch to keep things alive. There is risk to the mega fuse blowing if you do anything other than hook up the meter and return the battery to service for the test though...
 

c good

Active Member
Original poster
Dec 8, 2011
416
Thanks MrRsm and Littleblazer for the links and the info. I did some further testing for parasitic draw and didn't find anything suspect. So I bought a battery tester and the battery tested out to be perfect.

This morning I went out to start the Envoy after the battery sat on a trickle charger all night. It almost started....very slow cranking then no cranking at all on the second try.

So I started thinking it might be something other than a bad battery or a battery drain. I started thinking it might be a bad starter. So a little research, and jumping Post 30 and Post 87 on the starter relay should have got the starter motor engaging. It did not do anything. Not even the sound of a selenoid clicking......

So at this point I'm thinking it's a bad starter or selenoid or both. So....I get out my leather hammer.....smack the starter and selenoid a few times. Turn the key....and it starts right up!

So, I've confirmed that is the problem. I'm going to pull the starter and see if it just needs some new selenoid contacts or just cleaned and polished or if the brushes on the motor are needing to be replaced and the armatures cleaned up.

If I decide to replace the starter and selenoid altogether.....are there any brands that you would recommend? AC Delco, Duralast, etc... Thanks as always to everyone helping me keep my Envoy on the road!
 

mrrsm

Lifetime VIP Donor
Oct 22, 2015
5,984
Tampa Bay Area
ACDelco or Delphi..

This Instructional is Interesting and bears out my suggestion to Always Install A New Starter onto any GM 4.2L Swap Motor BEFORE Dropping it in place:


Hint... For Better Line Of Sight and Convenience... Wipe Down the Rain Flap shown in this Video and then Duct Tape it Up and Out Of The Way under the Driver's Side Wheel Well.

This Video provides a Top Down View when replacing the Starter when the Intake Manifold has been removed... just to give you a better idea of how things are situated when trying to access that area from below:

 
Last edited:
Jul 6, 2014
9,237
Could also be a connection too. Slow crank I'd look into that ad well
 
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c good

Active Member
Original poster
Dec 8, 2011
416
Update....It's interesting that it's starting better than it has in years. Something got jiggled around in the starter or the selenoid. It turns over with more authority...engages more solidly and spins faster.

I'm thing maybe oxidized contacts in the selenoid and the ring just shifted a little. It's definitely sending more amperage to the starter motor.

Now the question.....leave it alone and carry a leather mallet with me? Or dig into it! 😆
 
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mrrsm

Lifetime VIP Donor
Oct 22, 2015
5,984
Tampa Bay Area

If it were me...I'd Skip "The Mickey Mouse" and the Palaver ...and just Do It Right...

71dsayZA3xL._AC_SL1500_.jpg81brDM8dEGL._AC_SL1500_.jpg

ACDelco GM Original Equipment 4SX40-2FSA Positive Battery Cable
31r-xJi8zVL._AC_.jpg



ACDelco GM Original Equipment 4SX33-1FSA Negative Battery Cable

61H7nx+qaTL._AC_SL1500_.jpg


In THIS Video, Paul "Scanner" Danner explains HOW to Test your Starter Circuit and Wiring using a DMM and Perform a Proper Voltage Drop Test and he also explains WHY in the long run... using a Hammer or Mallet to "Jar The Starter to Life" will be a Bad Idea:

 
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Mooseman

Master Blaster
Moderator
Dec 4, 2011
22,550
Ottawa, ON
The hammer trick is maybe good as a temporary fix but it will eventually come back to bite you in the butt at the worse time. Git 'er done!
 
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c good

Active Member
Original poster
Dec 8, 2011
416
Thanks for the info and encouragement all. Hoping to dig into the starter soon. Even though it is working perfectly now.
 

mrrsm

Lifetime VIP Donor
Oct 22, 2015
5,984
Tampa Bay Area
For anyone following along on "The Weird World of Parasitic Draw" covered here... THIS is Important:

Performing a Ground Side Voltage Drop Test is a BASIC and VERY CRITICAL STEP in isolating otherwise Invisible Problems on Circuits where HIDDEN RESISTANCE is present in the Wiring and the need to discover any UNWANTED LOADS that will create mischief on Automotive Electrical Circuits.

I searched around for the Best Video Training Exemplar I could find that balances...

(1) Basic Electrical Theory (White Board Diagrams)
(2) The Unusual Use of a Diagnostic Tool (DMM)
(3) Visual Models of Loaded Electrical Circuits

...All meant to clear away any misconceptions about what happens when a Ground Side Circuit shows B+ Electrical Flow and what to do to solve this problem during your Troubleshooting Diagnostics

THIS Video meets all of those requirements and deserves a special place next to @Realism 's Classic Thread linked below regarding the Ground Locations in the GMT360 SUVs.:


THIS Training Video and "Screen Prints" are KEEPERS!


And here, Paul "Scanner" Danner and his son, Caleb work on diagnosing his Younger Step-Brother's Vehicle suffering with a Battery that has a Died from a Parasitic Drain using his redoubtable Snap-On Vantage MT2400 Graphing Meter:

 
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