How To Test An Alternator

This video will show you how to quickly determine if the alternator is bad or not.

Tools I use and recommend:

[williamhardy]

FINALLY!!! GREAT VID. INFORMATIVE. STRAIGHT TO THE POINT; NOT ALOT OF SMALL TALK. I DEFINITELY SAVED AND SUBSCRIBED!! 5 STARS!

[davidcarlisle]

Very good information 👍😊. I especially like how you showed the Voltage Drop tests, looking for bad connections 👍😊.

[ctcollinthib]

I found this video after my car died and ordered a multimeter. Had a hell of a time finding it again in my search history, but took notes and now need to reinstall my batteries and do the test. Thanks!

[phoso]

Best and simple instructions. Thank you sir!

[lauriekay]

Thank you for the easy instructions. I have a fairly new (6 months) battery not holding a charge on a 2001 Camry with 200k miles. I’ve never checked an alternator before so was hesitant to try by myself. Now I can! It’s the next step then on to the other possible causes of battery drain. Great video!

[anotherbadfriend]

Great video. My Jeep died tonight and this will help me troubleshoot it. If you're near the Target in D'Iberville I might need some help haha.

[gharv]

Happy 4th of July Rus!. Another helpful video, a tool I have and clueless about 😂. Definitely helpful! Cheers brother 🍻

[CookingwithStephennJacklyn]

Perfectly explained..you're spot on bro. Cheers 🍻

[damoose]

Thank You Rus!!!👍👍 Happy 4th of July Brother.✌✌✌

[truebeliever]

Thank you for the useful info. Much appreciated.

[cforrester]

Indeed - very good information to know & how to utilize a volt meter. I'll definitely give this a try. Thank you sir!

[rutabegger]

Glad I found this excellent video. I've been experiencing this start/no start issue with my 2016 GMC Sierra 5.3 for almost 2 years. Every darn time I brought the truck in to have it looked at the truck would start for them. My truck is acting up again, but I found something interesting today. Like the other day I put my new battery charger on to charge the battery. The battery showed 12.86v when off. I went try starting the truck and it started. Both times with the battery charger charging it started after not starting (only the one click was happening). Any idea what that could mean? Sounds like no charge was going to the battery until the charger was giving the battery juice. I tested my truck while running (no accessories on) and the battery was 15.45v. I hope you can guide me from here. Thanks!

[brandonoliver]

I just upgraded my 96 ranger 2.3l manual 5 speed 95 amp stock alternator with a 250 amp high output alternator, and I ran 4 gauge ofc from the alternator ground, that said test ground with a 4 gauge to the frame and then another 4 gauge straight from the positive output to the battery positive. And I put the original factory positive lead back on the high output alternator as well which ran to a starter motor relay where is split? And one positive goes to the battery positive, and one goes to the starter positive. I did not connect the battery positive to the relays positive. I left that one disconnected.
And it started fine, so power is going across the initial wire factory wire and getting to the starter, not even going to the battery. But 4 gauge straight from the alternator to the battery after it started fine, I was looking at it running under the hood, and suddenly the battery started bubbling and spewing out acid from the top covers. I'm about to go check the voltage at the battery and not leave it running, but just a second.... can I can determine whether or not it's getting too much voltage? And if that's the case, okay? The alternator should be good. Just, I need to get another voltage. Regulator or do I need a new battery? That can handle it?

[glennkaefer]

When you where testing for voltage drop was the car on and at idle or with all accessories one? Great video. At idle and no accessories on my reading is 14.95V so i it over charging?

[richardwinkler]

Thanks for this video I thought 1385 would have been a bad number but it’s fine.

[frankmarullo]

Good video Rus thank YOU FRANK FROM when are you gonna put up some cooking videos ???

[jacquesvanzyl]

Hi there
Is 13.7v charging rate at idle normal at idle? No auxilarys were on

[cajuncoinhunter]

Flukes are one of the best in the mobile field, and for bench top models also ....

[timbarnett]

Have you done the mult- meter test from HF? I have several free meters as gifts HF. Sit as many as you have an rest off same battery at same time to see how accurate they are to each other?

[DANIELROMERO-cvtu]

Great video
To the point
Quick and easy
I have a 110 amp on my F350 super duty.
Do you recommend I get a higher amp alternator if I pull a fifth wheel and have truck and rv lights, ac, radio and phone chargers on when traveling at night?