famfedyk

Just under 2 V between B+ terminal and battery positive. Much less at the alternator case and negative battery terminal.

Arsenii

There you go, that is exactly why you are not getting the charge - the wire between B+ post and the battery got busted somewhere. That will be quite tricky to diagnose.. Now you are getting in a bit of a dangerous area, I would really encourage you to ask a specialist to help you, it is dangerous to go in there without sufficient electrical knowledge, and not only for the car. You need to understand what you are doing.

Here you can find the wiring diagram for your Lexus (look for page 64 of the book), and here is a post with photos showing the wire you need. On the diagram, colors correspond to real wires in the car, find the wire that goes from the alternator to the 100A ALT fuse, and then check if the wire is intact. After that, check the the fuse itself, and the connection from the fuse to the battery. It is also important to check the positive terminal itself, it consists of a couple of pieces.

If it is the wire that doesn't work, there are two ways you can go about it - replace the wire, or run your own bypass circuit. Replacing the wire will be quite tricky, it will probably require you to take the whole front end off. The other solution is to run your own wire with fuse from the alternator to the battery.

Again, please, look for a specialist. There is quite a bit of current there, while it doesn't have enough potential to kill, it is really easy to mess-up. You know what to look for now, so the price for this repair should be quite a bit lower.

Hope this helps and best of luck!

famfedyk

I've already made an appointment to see a local repair shop that specializes in electrical issues. Thanks for all of your help.

famfedyk

Well, as it turns out, the issue was a loose wire or two underneath the larger fuse panel that is located next to the battery. The connections were arching. The local mechanic that deals specifically with automotive electrical issues took about an hour to figure it all out. He thought it odd that there were loose wires under the fuse box and asked if I had messed around with it. I told him no, but then again, I've only owned the car for just over a year so not sure what the previous owner had done when he swapped out the alternator. Charging fine now with the old alternator. Thanks again for all of your help and guidance.

Arsenii

Huh.. That explains why there was continuity.

An hour for that whole repair is not bad. I just wonder why would the previous owner mess with the alternator wiring, it doesn't make a lot of sense.. At least now you have experience diagnosing some electrical issues in your car. Hope it wasn't too expensive though..

In any way, glad you were able to solve the issue!

famfedyk

About the cost of a brand new alternator!

Arsenii

To tighten a couple of wires? That is a bit overpriced..

That is actually a good reason to learn how to repair cars yourself.. The best way to learn how to take apart some stuff in your car (in my opinion) is to go visit a junkyard and do the job you planned on a junked car first, since, frankly, those cars have nothing more to loose, so you won't really have to worry about breaking something.

Look through some videos, play around with the junkyard cars, that should give you a pretty good understanding of whether it is something you can tackle yourself..
Definitely let us know if you will get any other issues.

Hope this helps and best of luck!

famfedyk

Well, shop labor rate per hour is not cheap here in Southern California and if the mechanic spends an hour and a half of their time resolving the issue, I'm not going to argue with them over $ if they return a fully functioning car back to me that most likely would have taken me an entire day to troubleshoot. Everyone's time is valuable, including mine. I did what I could given the fantastic information I was provided and at some point (once I got to the resolution that there was something potentially problematic inside the harness), that is when I decided to take it to an expert (as you recommended as well).

I would love to have the luxury of wrenching on cars all day so as to gain more knowledge and just from the pure pleasure aspect (I am truly a gearhead...but not an electrical wiz when it comes to cars). But the reality is that I also have a full time job that pays me very well that occupies a lot of my time. So, I get paid well for running engineering analysis programs on my laptop at home as do mechanics who work in a shop tightening loose wires.

Thank you again for all of your help and be safe out there!

This too shall pass.

wmj259

Woops pls delete comment