blessed Posted January 17, 2005 Share Posted January 17, 2005 Hey guy's, Check this out...my dash lights dim and the transmission downshifts everytime I touch the brakes on my 91 ls. It sounds like it would be a sensor or something like that. Any suggestions? Please help. Quote Link to comment Share on other sites More sharing options...
wwest Posted January 17, 2005 Share Posted January 17, 2005 SOP, sort of......... Clean and burnish the battery terminals and connectors will help somewhat. When engine falls to idle, and rear brake lights add to load, alternator doesn't pick up the load right away so battery must fill in. Unless the battery can't turn the engine over for starting everything electrical is SOP. On newer models Lexus disables the torque converter lockup the instant you touch the brake. But then that should "feel" like an upshift. Don't Quote Link to comment Share on other sites More sharing options...
hughes369 Posted May 18, 2005 Share Posted May 18, 2005 Hey guy's,Check this out...my dash lights dim and the transmission downshifts everytime I touch the brakes on my 91 ls. It sounds like it would be a sensor or something like that. Any suggestions? Please help. ← check the posts, but there is a wire bundle on the drivers side trunk hinge that flexes and breaks. this cause your reverse indicator to light up when the brake is applied and also feels like the transmission is disconecting or downshifting. Fix that wire, and your car will not jerk anymore when touching the brake. For some reason this fixes a lot of problems. I fixed mine, with butt connector, but im sure that soldering the wire back would be cool too. later THE SNAKE 1992 LS 400 Quote Link to comment Share on other sites More sharing options...
blessed Posted June 7, 2005 Author Share Posted June 7, 2005 Hey guy's,Check this out...my dash lights dim and the transmission downshifts everytime I touch the brakes on my 91 ls. It sounds like it would be a sensor or something like that. Any suggestions? Please help. ← check the posts, but there is a wire bundle on the drivers side trunk hinge that flexes and breaks. this cause your reverse indicator to light up when the brake is applied and also feels like the transmission is disconecting or downshifting. Fix that wire, and your car will not jerk anymore when touching the brake. For some reason this fixes a lot of problems. I fixed mine, with butt connector, but im sure that soldering the wire back would be cool too. later THE SNAKE 1992 LS 400 ← Thanks Man! Cleaned the battery connectors well. Still didn't help. After more investigation, it seems to downshift from OD to 3rd (or D) once the brake is applied, however, if I take it out of OD and place it in D and apply the brake it stays in that gear when the brake is applied. Suggestions! Quote Link to comment Share on other sites More sharing options...
hughes369 Posted June 8, 2005 Share Posted June 8, 2005 check the forum for posts related to this, i did,...... but there is a wire bundle on the drivers side trunk hinge that flexes and breaks one of the wires in this bundle. . this broken wire causes your reverse indicator to light up when the brake is applied and also feels like the transmission is disconecting or downshifting. Fix that wire, and your car will not jerk anymore when touching the brake. For some reason this fixes a lot of problems. I fixed mine, with a butt connector, but im sure that soldering the wire back would be cool too. later THE SNAKE 1992 LS 400 ← Quote Link to comment Share on other sites More sharing options...
blessed Posted September 28, 2005 Author Share Posted September 28, 2005 Checked the white w/black strip wire on left side of trunk hinge and it was cut. Spliced it back together as you suggested and it fixed everything! WOW! Thanks! You the MAN! SOP, sort of.........Clean and burnish the battery terminals and connectors will help somewhat. When engine falls to idle, and rear brake lights add to load, alternator doesn't pick up the load right away so battery must fill in. Unless the battery can't turn the engine over for starting everything electrical is SOP. On newer models Lexus disables the torque converter lockup the instant you touch the brake. But then that should "feel" like an upshift. Don't ← Quote Link to comment Share on other sites More sharing options...
ArmyofOne Posted September 28, 2005 Share Posted September 28, 2005 SOP, sort of.........Clean and burnish the battery terminals and connectors will help somewhat. When engine falls to idle, and rear brake lights add to load, alternator doesn't pick up the load right away so battery must fill in. Unless the battery can't turn the engine over for starting everything electrical is SOP. On newer models Lexus disables the torque converter lockup the instant you touch the brake. But then that should "feel" like an upshift. Don't ← for you no military types, SOP= Standard Operating Procedure. :D EDIT: aw hell, he solved the problem...im late again! :( Quote Link to comment Share on other sites More sharing options...
jimtess Posted August 16, 2007 Share Posted August 16, 2007 Found the broken white /black wire and spliced it. No more downshifting and "R" indicator light when braking. Million thanks!!!!!!!!!!!!!! Quote Link to comment Share on other sites More sharing options...
jimtess Posted August 20, 2007 Share Posted August 20, 2007 also fixed my radio volume which no longer fades in and out. Quote Link to comment Share on other sites More sharing options...
jimtess Posted September 7, 2007 Share Posted September 7, 2007 also fixed my radio volume which no longer fades in and out. Scratch the last statement. My radio has started to fade in and out again. But it looks like a loose connection in the same area. Quote Link to comment Share on other sites More sharing options...
dieseldust Posted September 19, 2007 Share Posted September 19, 2007 check the posts, but there is a wire bundle on the drivers side trunk hinge that flexes and breaks. this cause your reverse indicator to light up when the brake is applied and also feels like the transmission is disconecting or downshifting. Fix that wire, and your car will not jerk anymore when touching the brake. For some reason this fixes a lot of problems. I fixed mine, with butt connector, but im sure that soldering the wire back would be cool too. later THE SNAKE 1992 LS 400 I wouldn't have believed it, but I found that the wire at the hinge was cracked. My garage fixed it and the problem went away. One garage was going to charge $$$$ to fix the problem by going into the transmission. My garage charged me $96 and this included an A/C service as well. A million thanks to the SNAKE 8^) Quote Link to comment Share on other sites More sharing options...
loydmike Posted March 12, 2014 Share Posted March 12, 2014 Hi, I am new to this forum and I'm experiencing the same problems with my 98 GS300. May someone please provide me with feedback as to what wire you're referring to so I could resolve this issue with the dash lights dimming while pressing the brake pedal. Thank you for your time and attention. Quote Link to comment Share on other sites More sharing options...
landar Posted March 12, 2014 Share Posted March 12, 2014 This trunk wiring issue only applies to 90-94 LS's. I would carefully check your ground connections to the chassis from the battery to see if there might be some corrosion. Do any other interior lights dim or just the dash lights? Also, this is the LS forum, not the GS. You might have someone who knows on that side. Welcome, Michael. Quote Link to comment Share on other sites More sharing options...
ideasplease Posted May 23, 2016 Share Posted May 23, 2016 Quote Thanks this was a awesome Find Quote Link to comment Share on other sites More sharing options...
Lucidtag Posted March 15, 2022 Share Posted March 15, 2022 Awesome find !! Its crazy how out of all the wires that wire is the one that snaps. I spliced it and it fixed every issue thanks a million!! Quote Link to comment Share on other sites More sharing options...
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