This is why Mechanics charge for Diagnostics! Car Battery Keeps Dying!

Channel: Rainman Ray's Repairs
Uploaded by Rainman Ray's Repairs on 20260728
Categories: Autos & Vehicles
Tags: parasitic battery drain, how to test parasitic draw, multimeter car battery test, car battery dying, diagnose electrical drain

Stop your car battery dying overnight by finding the source of parasitic battery drain. Learn to diagnose electrical issues using a multimeter. This guide helps car owners identify why a vehicle battery keeps losing its charge despite being turned off. If you are tired of jump-starting your car every morning, this step-by-step wal

This video from Rainman Ray's Repairs titled "This is why Mechanics charge for Diagnostics! Car Battery Keeps Dying!" details the challenging and time-consuming process of tracking down a parasitic battery drain on a 2012 Chevrolet Traverse.

The Problem: Parasitic Battery Drain

The Symptom: The customer replaced the battery, but the new battery still went completely dead overnight [00:43].

The

Frustration: Parasitic draws happen when an electrical component, module, or short circuit fails to power down when the vehicle is turned off, slowly depleting the battery over 24 to 48 hours [00:23]. Mechanics often dislike doing these tests because they are methodical, time-consuming, and require hours of observation [03:22].

Diagnostic Setup & Testing Steps

Tricking the Vehicle: To prevent

doors, chimes, and lights from turning on while entering and exiting, Ray manually latches the door mechanisms so the body control module (BCM) believes all the doors are safely closed [07:32].

Connecting the Multimeter: A multimeter is connected in-line with the negative battery terminal to measure the amperage (current) flowing out of the battery while the vehicle is in a shutdown, hibernat

ing state [05:22].

Normal parasitic draw usually ranges between 30 to 500 milliamps depending on the vehicle and active modules (like remote lock receivers or telematics) [06:04].

Eliminating Aftermarket Accessories: Ray notes that aftermarket additions—such as a plug-in OBD2 device and a dashcam—must be unplugged during testing, as the dashcam alone was drawing around 100 milliamps [19:21].

iscovering the Culprit

The Rear Wiper Motor: Ray notices that the rear windshield wiper motor attempts to move or park incorrectly every time power is restored [14:03]. Upon further investigation, the rear wiper motor's internal logic board fails to park properly, causing intermittent power draws [48:12].

The HVAC Actuator: The vehicle also suffers from a clicking blend door actuator for the h

eating and air conditioning system, which fails to report its position to the control module and continuously runs the small electric motor, further contributing to power loss [57:12].

The Conclusion and Solution

Long-Term Testing: After disconnecting the faulty rear wiper motor and replacing the clicking HVAC actuator, Ray leaves the car over a multi-day weekend to monitor battery voltage [53

:15].

Results: Over roughly 2.5 days, the battery voltage only dropped slightly from 12.76V down to 12.52V, confirming that the parasitic draw was successfully resolved through methodical diagnosis rather than guessing with a "parts cannon" [53:44].

https://www.youtube.com/watch?v=oD_28f8KgU4

This is why Mechanics charge for Diagnostics! Car Battery Keeps Dying!

Rainman Ray's Repairs · 99K vi

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Viewer Discussion & Comments

@MikeGreene-q8o

My EX was a parasitic draw on my bank account.

@Drekulviin

39:41 LOOK!!! In the back there's a Wild Dave in his natural habitat; it's a very, very rare sight, enjoy it while you can.🐈

@Thincup

this is the same problem i been having on my car for 3 months and its the same model and everything. i was about to send it to the shop but instead i just followed and bought everything you had in this video and fixed it myself. Ray you dont know how much i appreicate u. This video saved me a expensive repair. Thank You Ray!

@Countrybandit-x5f

Ray you dont know how much stress i been in. i been having this same EXCAT PROBLEM for 3 years on my favorite transverse and i couldnt figure out what it was. It was stressing me to the point i decided just to leave it parked in my backyard for 3 years, because i took it to 3 different shops and they all said it was gonna be 3k+ to fix. all 3 shops said they would have to take out the whole dash because it was a issue with something inside. i quit listing after they said 3k if im being honest, But thanks ray i fixed my problem. it was the rear wiper motor, and now i can drive my favorite car out of my 3. THANKS RAY! WOOOOOO!!!!! FREE KNOWLEDGE

@radar4067

The rear wiper switch is below the heater controls

@charliehargrave7458

YOU'RE GIVING ME A PARASITIC DRAW ON MY BRAIN.

@thommerklin

You need to go to Wilbert's in Bath, NY!!

@sponiebr

It was truly an all-time greatest hit, Ray!

@danielrivera8338

there is a guy his channels is pine hollow auto diagnostic he is really good at that

@PaddyOShenanigans

I learned parasitic draw diag way back when I was young from my auto shop teacher Marv Williams (RIP) He was the best teacher and mentor I ever had at that age. 73 Monte Carlo, no computers so back then it was meter and pulling each fuse one at a time to pinpoint the cause. Fired the parts cannon twice with a fresh battery and then an alternator, both were a nope. Ended up being the dashboard ciggerete lighter that two day prior to the drain had been held in a little too long by my GF while at the drive in, she pulled out red hot spaghetti, a piece of it remained in the socket and was fused across the terminals. Thankfully it's a diag skill I have not had to use many times over the years but one I've never forgotton.

@spencercarpenter5845

The rear wiper controls are in front of the shifter down below the heater controls

@johnfoley6500

Jeez you weren’t kidding about the lengthy process!

@Moe44125

Ray,

@DavidGuns

I love checking for parasite draw, after 35 plus years I still love checking for them. I gotten better over time and the good thing a lot of shops hate dealing with them so thats where I come in to help them.

@tobbex7372

My ex gf had a parasitic draw in her Chevy (Daewoo) and that was the washer fluid hose in left C-pillar that leaked down to a cablejoint/connecter that got shortcutted now and then. No squirt (because it squirted in the pillar) and goofy rear wiper moves just like you have. Just throwing this out there if anybody have use for it. Sorry for my bad english. Great job as always!