How to Test Automotive Grounds

www.fixmyoldride.com/real-fue... The newest article on my site takes a logical approach to improving fuel economy. I should have mentioned if the ground is poor the test light would be dim and on the meter it would read less then battery voltage. This result could indicate corrosion between the body and the connection. I always say in my posted videos that you need a good ground and power to an automotive accessory such as a power window or blower motor to make it run. I usually explain about the power side but have not talked about testing the ground side that much. On my blower motor video a viewer asked how does one check for a good ground. It was a good question so I made a quick video showing 2 methods of testing for a strong vehicle ground. If you want to see how to fix automotive electrical problems like a pro review this diagnostic tips page. www.fixmyoldride.com/strategy...

[@SomeGuy905]

As stated below, this is how you check for a ground, not for a good ground. For best results, use an ohm meter. Anything less than 5 ohms should be a good ground connection

[@AlejandroMartinez-pl4np]

How would you do that? That’s the video that I’m looking for.

[@evanleonardomirandacruz6031]

@@AlejandroMartinez-pl4npyou can directly connect one probe to the ground you’re looking to test and the other probe can simply go directly to your battery, I would recommend you to connect it to a distinct ground or good chasis, then, put your multimeter in ohm’s, anything close to 0 Ohm’s is good

[@patricke8627]

Finally. someone who understands the difference between voltage and grounding voltage. A lot of people think multimeter tests a ground, it does not

[@dznuttzonyachin7499]

was he not testing the ground wire ? 🤔

[@peterrocco2024]

Im going to add a few things, 1- do not use a test light with a LED bulb, it will not draw enough amps to verify a good ground. The best way is to have a headlight or i use a plow back light. If it will light a big non LED bulb you know it will most likely be able to handle the amp load for what the ground is for. 2- a fully charged battery is 12.6 volts even after sitting. Each cell is 2.1 volts x 6 = 12.6

[@ifixeditmyself1926]

Great video! To the point. Very clear 👍🏾

[@mlez7197]

definitely a great awesome video

[@feeneysmechanical6215]

Great video. But remember two things.If the circuit won't light a incandescent test light Then it won't carry current. Also Becareful with meter readings. Sometimes you can read voltage that's truly isn't there.

[@NewLevelAuto]

Greg Feeney look at you go

[@rickyharms8379]

the best way to find your best grounding point would be to use the ohms setting a see how much resistance there is wherever you choose to ground to.

[@md123420]

thanks a million great video and explaination

[@AF1MIDS]

Good morning my friend and nice to meet you! I love this video very detailed and explained with patience i appreciate you very much! I have diagnostic test steps from my factory service manual and i want to apply them one by one to my vehicle (2003 DODGE CARAVAN SE) but idk how to do it. Are you able to please show me how on a video? I would really appreciate the help alot. Thank you! 🙏

[@ntstudio28]

Thank you

[@lilcurtisdavidson4724]

I'm trying to check the ground on an aftermarket amplifier. What setting should the meter be on the test the ground? Tia

[@kevinferrell1739]

i tried that on my 2000 jeep. With test light, clip on the pos. post touched the ground on the engine/block and it does not light up. only if i put the clip on neg post then it lights up light on tester.. With testlight clip on neg post the light comes on when i touch both ac wires, and when i touch the light to almost everything under the hood the light comes on. My ac wont take freon is my main prob but im showing both wires on the compressor to be hot or have power. Even when the ac is unplugged. still shows power on both wires on the comp.

[@frankdavidson9675]

when testing a spark plug always set meter on highest ohm scale and read top of plug to threads any reading shows the carbon buildup which causes a miss fire

[@frankdavidson9675]

this a tip ---- if you need a 50 ohm resistor but you only have some 100 ohm resistors twist 2 100 ohms side by side read it now 50 ohms -----1/2 of 2 equal res. this works for any value as long as the 2 are equal

[@TheEdas007]

Actually you should do the voltage drop to make sure you have a good ground

[@nathanslaughter123]

You right, just the test light and meter like that I tells you it is connected to ground but you won't know it will preform under load unless you do voltage drop

[@jimflynn238]

correct

[@williambiggs2308]

Do you mean test voltage drop from the battery to the battery cable?

[@micheallumpkin9549]

Ya. You could have a totally insufficient ground and still get 12V. You should have put your meter on Ohms to measure resistance in that circuit.

[@jrtorres9052]

How do I check de emc grounds?

[@jelotech579]

NicE

[@INTERNA9]

THANX

[@feeneysmechanical6215]

Okay here's my opinion. If the test light is bright. the Circuit will carry current. I have had meters show that I had power. but check that same circuit with a test light and the test light won't light. Also by the brightness of the test light you can tell if you have a voltage drop.

[@lowellnewsome9908]

Can you use the ground on the battery

[@frankdavidson9675]

before you test ck your meter by conn both lead togeather should read low ohms it a good idea to twist the selector knob briskly back and forth this to clean the copper contact inside your meter once you do you will see a lower ohms reading which is correct exap----it may read 5 ohms once you clean it i will read 1 ohm this is in the leads copper wire.

[@jogon1255]

What happens if it does not read battery voltage?

[@frankdavidson9675]

your neg batt lead is starting point that black heavy duty lead fastion to veh. chasis undernethe on frame to ground on 3 times in my life i have found that ground conn loose causing havoc verfy this conn by looking under vech see that cable is tight --- grounding all metal of the vehicle

[@michaelpistilli5823]

Load the ground circuit engine running turn on blower and headlights take your meter and do a voltage drop test meter will do the math for ya dvom on millivolts postive lead on battery ground negative lead on body ground anywhere on engine the metal part of the vehicle and engine is the ground along with the ground cables this is a part of a general voltage drop test along with the postive side you could for example go from battery postive to a fuse in the fuse panel if that fuse is powered by the ignition switch now your checking that entire circuit including the resistance of the ignition switch this test should be around 100mv

[@frankdavidson9675]

a common joke about a new guy is ----he dont know how many ohms it takes to kill you. LOL

[@brandonjay5146]

Thumbs down check ohms from b- to suspect ground more ohms means less connection

[@huangyi8451]

Snapon

[@gonzalez7805]

Thank you