1990 Ls 400 Problem (car Stops While Driving)

[jbobba]

Hi,

I have a strange problem with my lexus and mechanic was not able to figure out for more than a week. I am hoping you guys will help me here. I will try to make it short.

I have 1990 Lexus LS400 and while driving I noticed the reverse light was coming on while pressing the brake. Soon after few days all lights came on dash board and then car stopped. We charged the battery and took it to the shop to replace a battery thinking it's battery problem. Sears told us it's an electrical problem not battery. So we went back to our regular mechanic where he replaced the alternator. Now the car is starting and ran fine from mechanic to home.

Next day while coming back from work car stopped 4 times and I can restart right away and start driving. so we took the car back to mechanic, he test drove the car and the car didn't stop. we got back the car and the car stopped on top of the bridge (I am 9 months preg, you can imagine the frustration). so now the mechanic took the car and not able to pinpoint the problem.

The car stops on him too but not every ride he takes.

I went through almost all posts in this forum and figured out related posts. I had the tail light come on once in a while, coolant light comes on almost all the time and the clock stopped showing for long time. Mechanic fixed the reverse light problem by correcting short wire in the trunk as mentioned in this forum.

Can you please help me? baby due any time and we would like to have a reliable smooth car for me to drive, rather than riding in Dodge Ram truck.

Thank you

jb

[Ericat53]

Now mind you, I am no mechanic or genius. All I can tell you is that I had a similar problem with another car I own. Just about the same story. As I was driving down the road one day, all the digital gauges and lights came on, and then went completely out. About five minutes later, the car started acting real sluggish, then died going down the road. These became common for the next few days until I could bring it in to the shop. After the mechanic looked over the alternator, the fuel pump, fuel filter, wires,etc....He finally came across the freeze plug, which he said was spraying water from the block. The water was shorting out the ignition wires. This is what was causing the instrument cluster to go nuts and making the car die he said. He replaced it, and I didn't have this problem any more. This car was not a Lexus, but my old Cavalier Z24. I don't know if this will help, but I hope you figure it out before you have that baby. Good luck! :D

[VMF]

there was a thread about it. guys found out that there is one wire in the trunk that was broken. i dont own firt gen LS so i didnt pay attention to this thread. but if you will look you will prolly find it. i remember the wire was too short and broke. by fixin the wire the fixed the problem

[VBdenny]

Yeah, I also remember a thread about a wire in the trunk. The wire is located in the left hinge and was made too short or something. I think it was a black wire with a white stripe. Fixing the wire fixes the problem. The problem is that the thread wasn't named about the wire. If I can find it I'll let you know

[VBdenny]

Luckily, I copied the infor and saved it here is what was posted to fix the problem

Hey Hoffmnjp

Im about a week late on your post I dont know if you have fixed it yet but if not heres your fix.

You do have a bad ground.

Very common in early LS's.

Open the trunk on the drivers side trunk hinge (curved bar attaching trunk to car)there is a black plastic piece running the length of the hinge protecting a small wiring harness that runs through the trunk hinge.

Pull that down and out of the way.Pull the harness out of the hinge it kind of runs down the hinge and then goes up and makes a u turn pull that out .You can pulldown the trunk liner on drivers side and see where it snaps on to a bolt pull that off of the bolt to give yourself a little more wire length to work with.

Now you will see where the wires make a uturn inside another plastic piece.Unravel the tape in this area and remove the plastic piece.

You will find a broken wire (white with black stripe) made a little to short at the factory.

Splice in a small 2 inch extension betweeen the broken ends preferably solder it ( use butt connectors that you crimp on or twist and tape if you must.)

Tape the harness back up.

Put it all back together.

[wolver1ne516]

most automobiles need a ground wire for the electrical componants to work,and the electrical componants are needed as well to make the rest of the car to work too.

I've done some research on my 91 LS400 and noticed several grounding points all over the car. one might not be grounded.

unfortunately...I'M NOT SURE WHICH ONE IS WHICH.

[90LS400Lexus]

I know this topic is a little old and I am sure the problem has been repaired (hopefully). Anyway- my 1992 Buick Park Avenue Limited did this a while back. It would stall, but start back. Soon, it would take longer and longer to start. Turned out to be a cam or crank shaft sensor. I am not sure if the LS400s have this or not. My old 1991 Honda Accord LX also did this- but it stopped and would not start back at all. Turned out to be the distributor cap, which is a very common problem on the mid 80s to mid 90s Accords.

[leeelooo]

FYI:

Your guys are Great!!!!!

This thread solved my 4 probelms at once:

-- 2 years ago, my Bulb-out Indicator was on every time when I 1st time press the Brake after started the car

-- 6 months ago, my driver side front brake became Not Smooth; made nosie when appling brake

-- last weekend, all the sudden, my trunck could not be released from release switch

-- last Monday, my transmisison can not be shiffed to up gear, after i turned lights on and then got "R"

After i read this, i checked my trunk hinge, YOU ARE RIGHT, there are 3 comlete broken wires, White, Yellow and White/black strip. Then after I reconnected them back all of above 4 problem fixed!!!

Many Thanks!!!

ps. my care is 93 LS400 with 129K miles. to me it is materal issue as those 3 wires are very hard while compare to normal wires....

[Sanch_B]

1998 Lexus LS 400

 I’m hoping this is the fiX to the reason my radio cuts out when I hit the brakes. Sometimes the speedometer doesn’t work for the first 5-10 mins into a drive but then kicks in. Also lights flicker and humming noise is made coming from radio I believe. Seems to me like when the battery has a good charge on it that all of the electrical components like the radio and the speedometer are all working well but if I let my car sit for 24 hours or more sometimes it doesn’t wanna start due to the battery being drained. Now I don’t know if there is something that is drawing power when the car is off but it wouldn’t surprise me if there is something doing that which is causing the battery to drain. But once I jump start the battery car starts right up and at first the electrical components are having their issues like the radio shutting off when I hit the brake and the lights and the radio Flickering and the speedometer sometimes not working but once I’m Driving for a good amount of time and the alternator has had time to charge up the battery those issues all go away. Hope I’m in the right place and on the right path to finding a solution if anyone out there has any ideas please let me know. I understand this Is an old forum thread but if you happen to stumble across this  post, please feel free to lend Some Good advice.

 Thanks, Brandon

[paulo57509]

Read through this thread:

https://www.clublexus.com/forums/ls-1st-and-2nd-gen-1990-2000/656360-all-my-crazy-lexus-issues-solved-ecu-leaking-capacitor.html