1999 Toyota 4Runner Alternator Replacement and Wire Repair | How to tell if your Alternator is Bad

I was in the process of replacing my timing belt when I noticed the 3 pin plug for the alternator had a corroded/burned pin. I had a Denso remanufactured alternator I planned to put in during the timing belt job since I was having electrical issues. I ordered a new connector pigtail and I show you how to install it properly. I wasn't originally planning on showing how to replace the alternator but since the new remanufactured one was bad out of the box, I show how to swap it out. Hope this was helpful and thanks for watching!

Disclaimer: work on and modify your vehicle at your own risk. You are solely responsible for your actions. Always use proper safety equipment for the job.

Timeline:
Intro: 0:00
Burned/corroded plug repair: 0:27
Bad remanufactured alternator diagnosis: 5:46
Alternator replacement: 8:44
finally fixed: 1646

find the connector repair supplies here:
(I may get commissions for purchases made through links with "paid link" next to them, buying from one of these links will help me support the channel at no extra cost to you.)

[WheelKid]

Timeline:
Intro: 0:00
Burned/corroded plug repair: 0:27
Bad remanufactured alternator diagnosis: 5:46
Alternator replacement: 8:44
finally fixed: 1646

find the connector repair supplies here:
(I may get commissions for purchases made through links with "paid link" next to them, buying from one of these links or using my coupon code will help me support the channel at no extra cost to you.)

[Mitsuneto]

Stuck at an Orielys 20 hours from home on a road trip when my alternator died and your video single handedly made replacing it so much easier. Thank you.

[lauravetos]

thank you so much for the tip on how to get the alternator back in with the c-clamp trick. I am a 61 year old mom who was able to do it thanks to you. good job!!!

[sherman]

Wonderful video. I had voltage around 1370 in my 2002 Tacoma. I replaced my alternator and it continued with low voltage output. I ordered everything you use in this video and just completed the wiring and fitting. Voltage is now at 1430👍
Thanks

[grahamellis]

Very helpful, thanks for taking the time to show everything well, especially testing the diode, well done 👏

[gimmetaco]

Dude. This is a most EXCELLENT video. As simple of a swap as this is, you covered every nuance and even were able to troubleshoot a bad reman part. Nice job! I love my 3rd Gen (on our second one now). Just subscribed and keep up the fine video and instruction work!

[smrtnz]

Great video with troubleshooting of wiring issue, And Alternator diode check, removal and install. I’m in the process of swapping out Alternators so that I can rebuild my original Japan Denso Toyota alternator. You can’t find original OEM anymore (stateside) all remanufactured. So I bought a cheepo just to get by till the original is ready to be reinstalled. I’m replacing both bearings, voltage regulator, etc. and cleaning thoroughly.

[prettyboy]

Thank you so much. You saved me and my 4runner!

[dominicbassis]

Great video I just did my truck today had similar problem with connector corroded.

[rolandvz]

at any time you had low voltage dips did the battery light on the dash come on?

[mynorcorona]

The most informative video I found yet as I'm working with this problem. I'm trying to figure out why the wire melted for high resistance. Can you give me any advice on what I should check and then follow this video through to completion ? Thanks so much in advance

[brendanmcquillan]

The plug on my 4Runner looks the same as yours and has black around the hot batt terminal. I also get a lower voltage idling in gear, and the truck has a heavy electrical load... Which i think is normal for the truck and maybe i never noticed it.

Would you do this repair in hindsight if your alternator was still functional?

With your new alternator pigtail and new alternator, do you still receive a low voltage at idle in gear?

Thanks for the video and insight!

[rallypoint]

Very cool vid!! What volt meter are you using and where did you tap the wires on? I have a blown clock and wanted to throw a volt meter in there.

Thank you!

[michaelowenalonzo]

Where can by that positive terminal cover that connect to alternator

[brianbay]

What were the symptoms that you were experiencing that led to you initially changing the alternator? We're you getting an intermittent battery light?

[Kyle_House]

How did you get the clock swap for a V meter ??? Link for it??

[tprblazingninja]

Hey @4WheelKid just looking for an update How long did this alternator last you?

[yungMajin]

Hopefully this is my problem with my 99 4runner. My interior lights go dim when i turn off the car. Im tired of missing work just because it doesnt turn on some days and even with a jump it wont turn on sometimes

[thomasjefferson]

how she holding up? just ordered a new denso alternator from rock auto on my 98 gen 3 runner

[cf]

What is the original voltage supposed to be with the stock Denso?