1995 - 2000 GM OBS Truck Parasitic Draw Diagnosis ~ Voltage Drop Testing Methodology (Chevy & GMC)

In this video we will be going thru how to locate and repair a parasitic current draw causing the battery to prematurely discharge. A parasitic drain is caused by a circuit being powered on abnormally after the vehicle has been shut off. We will locate the problem using the technique of measuring voltage drop across the fuse for each circuit in the vehicle. This approach works for both single battery gasoline trucks, as well as dual battery diesel vehicles.
The truck illustrated is a 1999 Chevrolet K1500 Suburban LT, old body style (OBS) GMT400, but the parasitic draw diagnosis procedure I share with you will be the same for any 1995 thru 2000 OBS truck or SUV. So Cadillac, Chevrolet, and GMC for Escalade, Cheyenne, Silverado, Suburban, Tahoe, Sierra, and Yukon across C1500, K1500, C2500, K2500, C3500, and K3500 weight ratings. This approach will be similar, with only the interior design / fuse box location, being different than shown, for all earlier OBS trucks from 1998 thru 1994.
The eBay and Amazon search links below are paid links, for which I may be compensated and earn a commission, if you choose to buy the parts and tools shown in this video thru them:
Uni-T UT210E clamp type ammeter: ebay.us/M1VzJN or amzn.to/3XbHJC2
GM factory service manuals for OBS CK truck models: ebay.us/MR4JXW
The following discontinued sunshade parts are unique to the SUV body styles, and will only fit 1997 thru 2000:
GM 15001755 (LH) and GM 15001756 (RH) illuminated sunshade in red: ebay.us/KAv6Ap
GM 15745401 (LH) and GM 15745402 (RH) illuminated sunshade in gray: ebay.us/XVHhUU
GM 15745405 (LH) and GM 15745406 (RH) illuminated sunshade in neutral: ebay.us/gVkkmM
GM 15745403 (LH) and GM 15745404 (RH) illuminated sunshade in blue: ebay.us/cFmjUP
And if I've saved you some $$ here, consider some coins for the coffee tip-jar! ko-fi.com/drshock
1995 1996 1997 1998 1999 2000
Chapters:
0:00 - Problem overview
0:26 - Service manual guidance on parasitic load testing
4:58 - Voltage drop testing methodology
11:18 - Confirming a suspected parasitic draw
15:05 - Repairing a confirmed parasitic draw example
18:22 - Repair approaches for a defective sunshade vanity mirror cover
#drshock #obstruck #obstrucks #gmt400
Disclaimer: DrShock, the alias for the human content creator for this KZbin channel, is not responsible for any damages, injuries, losses, or liabilities associated with any repairs, upgrades, or maintenance performed on yours, or any other, vehicle whatsoever. No warranty, express or implied, is made as to the accuracy or completeness of any information provided within this channel. Viewing and using the “as-is" information of this channel is totally at your own risk. Always wear personal protection equipment and follow appropriate vehicle manufacturer service manual guidelines with original manufacturer parts only when performing any repairs, upgrades, or maintenance upon any vehicle.

[@laurijorgenson6683]

New subscriber. Great content. I found you because I was looking for Tech2 information. I am working on my sister’s 1999 Saab 9-5 brakes and need to bleed them using a Tech2. It just so happens that I have a 1999 Chevy Suburban too so finding your channel is golden! I will be investing in a Tech2 clone to use for both vehicles. I have found several great videos you have so thank you very much. You do a great job in producing your materials!

[@rafaelrverduzco8570]

Thank you for this video. very good

[@edberry925]

Always interested!

[@Driosenth]

Didn't even need to wait for the reveal. The moment I saw it was an OBS with updated interior I knew it was the lamp for the sun visor mirror. Those are notorious for the switch failing and getting stuck on without the owner knowing.

[@2CODO1963]

You are absolutely correct, @Driosenth, that is exactly what happened to my '97 Tahoe. And the way I discovered it is when I lowered the visor the mirror cover was hot to the touch.

[@camaromustangmods3327]

I love your channel since I picked up my 99 2 door Tahoe. Good info. Any way maybe on a video on the cruise control of these years obs? I've had a few and current that have this issue.

[@DFJ1997]

This is a great video. I just had a question that no shop seems to figure out a solution for. I have a standard 3 miliamps or almost 14 volts pulled from my battery on a 95 Chevy truck. I have a 2.0 voltage draw on auxiliary port A eventhough there is no fuse in said port and the voltage jumps between 13 and 14 when I have the turn signal on and if I turn the headlights on it drops to 13 then fluctuates between 12 and 13. Everything else reads 0 all across both fuse boxes. Any ideas?

[@DrShock]

Voltage on a circuit without any fuse installed would suggest to me a short to battery positive exists somewhere along the length of that section of wiring harness. Would be very tedious and time consuming to track down. I doubt many shops would want to get involved with it.

[@jimmycorbett4611]

Would this work for 1988-1994 obs Chevy trucks?

[@DrShock]

This troubleshooting technique is definitely applicable to those years, but of course where fuses are located and appear will be different than shown in this video for 1995 and up.

[@stacymathis1792]

Dr shock can you rebuild my Chevy injection spider ?