Good way to know if you have a bad alternator

[thomasforan]

So very easy test, get a DC voltage tester, with the engine off test the voltage at the battery terminals it should be around 12vdc. Next start engine and this time test the voltage again at the battery terminals and now it should be over 12vdc. If it is great everything's good if the voltage doesn't change or is less than the battery then the alternator is bad. The sound from the alternator may also indicate a bad bearing in this case remove the belt and see if you can easily spin the pulley. If it's got a bad bearing you'll feel it as you spin the pulley by hand. Good luck!

[NKWoodworks]

For anyone wondering, that noise is normal. Even when the trucks are new they make that noise. The alternator will always make that noise. What you really need to watch out for is a loud groaning or squealing. That means that the rear alternator bearing is dry. If the alternator itself is bad, it will make a growling noise that sounds similar to a bad power steering pump

[markknights]

this was helpful. thanks for taking the risk and making the video :)

[johnfranks]

That sends 12v signal to your alternator to turn on and produce power. That’s what the noise is. Your alternator is doing it’s job. Diagnose it by putting a volt meter on your battery, if it’s reading between 13-14v your good and it’s your battery. Those batteries are shit anyways so I don’t doubt it, Their super cheap.

[pzafamily]

Good shit dude ... damn good troubleshooting broh

[jorgeramirez-quxu]

Good looking out bro ima try that tomorrow apreciate you

[thelasthokage]

Yeah but usually if the alternator is bad, you should replace the battery too to be on the safe side

[MacAutoDiag]

That noise is the alternator charging. GM alternators make that noise that's normal. The battery looks swollen or something. Those yellow and red top batteries are trash

[ElGhostPresents]

No crank no start, check the starter, connections. It started so it can't be relay or fuses. The alternator can drain the battery even if it's new. So if it does, then yeah the alternator. But if it doesn't and just have trouble starting, check starter and connections.

[mattackermann]

Just noticed mine started making noise. Right after battery light and "battery not charging" warning came on. New one on the way, replacing tomorrow.

[Nowaybro]

dry cell batteries only last 1.5-2 years max. They aren’t all that good just expensive. They can’t be charged and they don’t produce any more energy than a standard one.

[BJBRUNOHO]

Battery 🔋 I have a 3 year warranty you better use it while you can type shit

[tyde]

Don’t that mean you have a bad battery? It kept running after you pulled the the plug

[Blake-qc]

Dude that noise doesn't mean its bad

[eralieshpulatov]

I think it’s coming from the cable which you disconnected maybe it’s good alternator in good battery but bad cable?

[johnfranks]

Or it could be your starter, either shitty connection or bad starter