Jeep Wrangler JK/JKU | DIY Alternator Replacement | Whining noise!?

Jeep Wrangler JK/JKU | DIY Alternator Replacement | Whining noise!?

The Jeep was making a weird electrical whining noise and had faint electrical burning smell, so I replaced the alternator in my 2008 Jeep Wrangler Unlimited with the 3.8L engine!

Replacement Jeep JK Alternators!:



Desert Detector says:

Looks like i'll be replacing mine. Thanks for the video!

Hank Smith Jr says:

Thanks for the vid as it is very informative. As a master mechanic I can say that it that the noise is caused by bad diodes within the alternator. Jeep JK's are famous for this.

brian gustitus says:

My 2010 is making the same noise, someone said it could be the bearing on the alternator… I figure it will just be easier and less time consuming to replace the whole thing…. thanks for the video!

Thomas Lucier says:

Great video! My wife's 08 JKU was making the same noise. Thanks for going through the details of changing it out. I had it changed in no time at all thanks to you!

Scot Hardesty says:

Definately helped! Thanks!!

Andrew Sharples says:

Nice video. Watched yesterday and it looked simple enough, so I did it today. Took less than 45 mins on my '08 with 154K miles. Jeeps can make a bunch of weird noises. One trick I used to be sure it was the alternator was to take a piece of a 2×4 and hold it on the alternator while it was running. The vibration came right through the wood and I was absolutely sure this thing's days were numbered. Thanks.

Wun feather says:

Perfect video! My daughters jeep has an alternator problem and she lives about three hours from where I do. By watching your video, I can see exactly what tools I need to bring to do the repair. You mentioned the sizes of the bolt heads, and showed how to remove the tensioner and the belt schematic. Well done! I always bring my Milwaukee M12 Fuel Ratchet, so the removal of bolts and nuts goes way faster in the field.

Rob Cunningham says:

Definately helpful. That's exactly the noise mine was making as well.

Principal Skinr says:

Great video. My 2008 just started doing that. The dealer wanted $650 bucks to replace it! Ouch! They told me it is a 160 amp, but everywhere online I see 140 amp. Any idea which came on the 08 Rubicon?

Rod Perez says:

Great video. Had exactly the same thing going on w/ my 07. Followed your steps. Thanks homeboy. My alternator still gets HOT. You having that problem?

bradley gregg says:

Just another note for anybody experiencing this same thing/hearing this same noise. As the alternator is driven by the serpentine belt that changes speed with the engine speed, you will hear this sound change (go higher pitched) at higher engine RPM. If you're unsure of where it's coming from, you can (VERY CAREFULLY, since the pulley is spinning) use a long screw driver or an auto stethoscope and touch the metal end to some stationary part on the body of the alternator, and listen with your ear touching the handle. It should sound very distinctly like the noise here (only louder). Good explanation in the video. Thanks!

Raul Angel Fonseca says:

After doing an alternator replacement you should check the power output to verify it is putting out the correct power. Better at the time your doing the work than later when your out and about.

Raul Angel Fonseca says:

Hey folks please remember to disconnect your battery before doing any electrical work on your vehicle.

Wade Yazza says:

What size belt do you have?? On your jeep. Mine was a pain to get off and it wont fit back on.

Ray lu says:

Thanks for the vid. What is the brand and product number on that alternator? The link in the description did not work for me. Thanks!

mando talamantez says:

146,000 miles on my 08 JKU and just about to replace the alternator. Already took the old one making the same noise out and about to pick up the new one at the parts store. Thank you for uploading this video.

Ryan Rodriguez says:

Thanks for the help ! I used this to fix my JKU with 125k miles tonight

j r says:

Excellent teaching video, when you mentioned the symptoms you nailed it for me.

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