Ls 400 1999 Total Electrical Power Failure In Heavy Rain

[RonanB]

Hi Guys,

I thought that you guys would be the best people to ask about a problem I'm having with the good ol LS 400, in very heavy rain and driving on a motorway twice this has happened where all electrical power is lost completely and then after about 10/ 20 seconds it returns as though nothing has happened. As you can imagine this is quite un nerving. Would love to hear if anyone else has had this problem or knows anything about it.

Kind regards

Ronan.

[cruisermark]

hi

you very rarely get electrical gremlins on the LS range

I would :

a) get the Battery checked - check connections are tight and clean

b) get alternator checked

When i had my Mark 4 i used to get a scenario where all the lights/dash etc would go out but the engine would keep running - this turned out to be a faulty ignition switch.

if (a) and (b) are found to be ok then when the problem occurs again try wiggling the key in the ignition to see if makes any difference to perhaps indicate wether its the ignition switch.

hope this helps

[cruisermark]

sorry i dont know why the smileys are there - i never use them

[PhilipK]

sorry i dont know why the smileys are there - i never use them

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[Graham Gardner]

Not another thing to look out for on the mk4?

[Malc]

............. the need to wiggle the ignition key in the switch was also a bugger of a feature with my Mk3 for a while ..... then like all good Lexii, the problem resolved itself ( fingers xd )

BUT this is not a problem only to Ls400s, my indy chap told me it was a feature on other cars too from time to time.

Malc

[ambermarine]

I to have experienced the problem of lights out on the dash and no electrics while driving along under normal conditions .It happened a couple of month ago and it happened last week I touched the ignition key and everything returned to normal.

I have a virtually brand new car so it is'nt a worn out switch.

I have now done some extensive research and it turns out this switch is fitted to dozens of different Lexus and Toyota models as well as a host of other makes of car.

Unlike the earlier mark1and 2 the switch is not integrated into the ignition barrell but just fitted on the end with a couple of screws and as a segmental coupler exiting the ignition barrell to slot into the turning segment of the switch.Plenty of room for errors there I think, the replacement switch from Lexus UK is £72 +vat ,in the states it is $70 which is about £20 cheaper .

It is not a difficult fix as it just plugs into the circuit when fitted.

Involves removing the dash panel underneath the steering wheel above the pedals, dissconect the plug to the switch change over the new switch and reverse fit.make sure the Battery is disconnected before starting the procedure.

Lexus US part number is 84450-16080 and it does fit universal, I quoted the europe part number to Lexus UK but it did not come up on their screen so stick with the US part number.

[Maduggo]

Had this issue on my mk3 400, driving along as normal in normal conditions, dry roads, nice weather, and poof, like magic all the dash goes blank, stereo shuts off, steering goes heavier but not as bad as no power steering at all.

Maybe 10 to 20 seconds later dash lights back up, steering goes to normal smooth control and on you go.

I don't think it's the rain as it happened to me in the dry, with lights off, also at night lights on, but it did happen in the rain as well.

Never found the issue or what causes it. Seems several others had had the same and similar issues.

[RonanB]

Hi Guys,

Would just like to thank all of you for the swift and helpful response, I will work my way through the suggestions and let you know how I got on.

Kind regards

Ronan.

[Titch LS]

For what is now an old car I don't think we can complain if the odd niggling fault occurs on our 400's now and then. Most other cars of similar age to ours are already scrap or are ''old bangers". My 15 year old LS still drives smoother than any car I've had.