CBSSYS

OK! Bought the used part. And was in Detroit and returned the first one and got a cash refund. Now I want to put it in but would love to see how is the best way to attack this. It is not in my manual. Any ideas? Just hate to tear in blindly. This is about the most complex part with more plugs than I have ever seen. Cannot wait to see if this does it. It would be wild it the SRS red warning light went out too.

Tom57

It looks more complicated than it really is. The hardest part is getting to the JB with room to work. You'll be kneeling outside the vehicle and working in the driver's side footwell area. The emergency brake arm and pedal makes it difficult. Remove the fuse box cover. Then peel back the side rug that covers the driver's side JB to gain access to the JB.

Next, remove the two (possibly three?) long machine thread bolts that attach the JB to the footwell. They are located in the opposite corners of the JB. Next, with the JB unbolted off the sidewall, all of the wire plug-in connectors to the JB are easily removed and re-inserted into the replacement JB. You can mark the wire connectors for peace of mind, but I think the connectors are all different sizes so you can't inadvertently plug one connector into the wrong spot on the JB. Do not remove the relays (square little boxes, one is brown color) that are plugged into the old JB. Install replacement JB with all wire connectors plugged in, and bolt into place. NOTE: There is a little plastic square-shaped "ear" on the corner of the JB that hooks into the side footwell. Place carpet wall back and cover onto fuse box.

Hope this helps.

CBSSYS

Tom, we bought that part, my son-in-law installed it yesterday and the problem is GONE!! Hope it stays fixed but your fix seems to have done the job. The install is not easy but is doable. The wires going to all the plugs, esp the front ones, are very short but not impossible. Thanks!!

Jim in Chicago

swegyptian

I may have developed this problem last night. I had the car battery out while doing to some other stuff, and then last night I noticed that despite the cluster being lit, I had no lights on the center console for HVAC and such. I do not have NAV in my car. I also noticed that the compass seems to be off. Are these issues in any way related?

Tom57

That's great news Jim. If the Nav screen doesn't go bright at night, the problem is solved.

Tom57

Start by checking fuses. It's possible a fuse blew when re-connecting the battery.

swegyptian

Thanks, Tom. I read through the fuse list in the owners manual, and I didn't see anything related to the issue that wouldn't have also included some other kind of failure. Then later in the evening, the lights came back on and off a few times.

The dimmer still works for the cluster, too.

Tom57

If the console lights came back on, then it's not likely a fuse.

You only have part of the symptom I had - console switch lights dark - since you don't have NAV (symptom - screen is bright at night). It may be the the driver's side J/B. But in post #20 above, the issue was resolved by replacing the dimmer switch / rheostat. But a new dimmer wouldn't have solved my issue, and CBSSYS tried that too and he ended up returning the new replacement dimmer.

swegyptian

So I got a replacement used junction block from an ebay seller, and tossed it in. It still really bright outside, and I have no garage, so I'm not sure if the problem is solved. But, I do now have a flashing AFS light, and VSC and ABS lights are on. Would these also have something to do with the same driver's side J/B?

swegyptian

I also learned that I could not shift out of park with the replacement JB.

I swapped back to the old module, and the problems seem to be gone.

dreulandb

Following up on Jim's post #33 above. Confirming that the drivers side J/B did fix this (intermittent bright NAV screen at night)!

His son-in-law

Tom57

Nice job on the DIY swap of the driver's side J/B, and helping out your father-in-law!

Bucketlist

I have a 2004 LS430 UL. I am reviving this thread as i have the same symptoms others have described.............. Headlghts come on when outside light levels become low. Then the NAV screen backlighting stays in the bright daytime setting. Additionally i lose the green backlighing on every dash and console switch. So it appears that replacing the Fuse Block in the driver footwell kick panel has fixed this issue for a few owners in this thread. Has anyone one else encountered this same problem? If so did replacing the fuse block remedy the issue?

CBSSYS

So I see others have had this problem also since my Son-in-law David did the research, replaced the part, etc. It has been perfect for 17 months! None of those issues returned. The most important thing is being sure the seller will give some warranty. This part is not small, has lots of potential failure points and it has electronic components inside. I tried to fix the problem by replacing the brightness ****/switch but that was NOT of any help. I am SO pleased about this fix. It was a very irritating problem. I saved the old one just in case Lexus or someone else wants to tell us what to replace in these so we can fix them.

JimInChicago

Tom57

I'm the O.P. of this thread. This is a rare issue, so if you're looking for a larger sample size, you'll be waiting a long, long time. Very very few examples, and even fewer who DIY fixed and then came back to report on CL. I can tell you that I spent several hours of research time, including contacting Lexus/Toyota electrical engineers who didn't have a solution to what was, at the time of my original post, a one-off original issue. I finally broke down and had my L dealer try to diagnose the issue. The dealer had my '01 for 3 days. The dealer used their research resources, including contacting Japan. Their solution: install a new driver's side J/B (I won't quote you their price). I picked up my car, found a used J/B, installed it, and haven't had the problem again in 4 years. Since the L dealer parts manager is a friend, the dealer charged me 1 hour to diagnose. I shared my solution on CL. If you have the same issue, the easy and cost-effective solution is documented in this thread. Good luck.