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We had a very difficult one last year in the RX330 forum involving overhead lights & sunroof and we it traced to a harness junction just like this.
One person had a loose connection and snapped it back in and everything worked perfect.
Another person unhooked the battery and discovered there was no continuity thru the junction and realized he had bad plugs
I would look hard at Oldsurfer's fix, it appears to be Junction J3/J4- this plug is in common with your interior lights & dash cluster circuit(circuits posted above).
Cheers.
Last edited by Margate330; Mar 3, 2021 at 12:37 PM.
We had a very difficult one last year in the RX330 forum involving overhead lights & sunroof and we it traced to a harness junction just like this.
One person had a loose connection and snapped it back in and everything worked perfect.
Another person unhooked the battery and discovered there was no continuity thru the junction and realized he had bad plugs
I would look hard at Oldsurfer's fix, it appears to be Junction J3/J4- this plug is in common with your interior lights & dash cluster circuit(circuits posted above).
Cheers.
Oh Ok so J3/J4 is the connection OldSurfer cleaned up.
I did check that and didn’t see any corrosion and the matings are flush when insertsd.
I did pull one end of the J3/J4 connection and turned the ignition key. no other lights / body components went out. So that junction does appear to be localized with my symptoms but I don’t know how or why yet.
Stupid question I’m sure but is there a particular pin in that junction box that is power? Should I check all the pins with my circuit tester?
Yesterday I did the same steps again for the J3/J4 connector.
Removed the connector from male leads. Used a toothpick to coean the connector slots and wire pins. Reseated the leads. No change.
This morning, go to drive for work. Said to my wife - this time it’s going to be working, and laughed. Turn the key, and everything works again. I laughed so hard I was in tears. Drove home fine this afternoon too.
Hopefully it won’t magically reappear but I know where to look if it does.
Yesterday I did the same steps again for the J3/J4 connector.
Removed the connector from male leads. Used a toothpick to coean the connector slots and wire pins. Reseated the leads. No change.
This morning, go to drive for work. Said to my wife - this time it’s going to be working, and laughed. Turn the key, and everything works again. I laughed so hard I was in tears. Drove home fine this afternoon too.
Hopefully it won’t magically reappear but I know where to look if it does.
Thanks for abiding my ignorance!
Hey, I'm not sure which pins, they were 2 in one of the corners. My guess is if I tracked them by wire colors the power or powers to the affected circuits -- after they left the BCM -- got pulled to ground through a lower resistance route. I used little emory boards, a lot of contact cleaner and compressed air to clean both the male ends in the junction and the female connecters that go into it. If you're careful you can use a straight pin or small paper clip to do a gentle drag test on the female ends to make sure there is still tension to grab the pins, but if it runs now let sleeping dogs lie.
I'd check that sunroof drain vent. Am 90% sure mine evolved from that.
Intermittent problems are so hard to find and trace.
Lexus parts sells individual pins [or Lexus of Austin was kind to sell me some]. They were expensive and you can possibly clip a connector from salvage yard. In desperation I might as well just hard wire the connector ... solder + shrink tube the wires. [what is the likely hood that you will need to separate the connector .... ha ha famous last words]
