98 lexus Ls 400 electric problems
09-27-12, 04:40 PM
#1
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98 lexus Ls 400 electric problems
I beleive the battery was crossed when it was installed and since then i have no power to anything in the drivers compartment, dash lights, sun roof, windows and door locks, interior lights, etc. do not work . I tried to check fuses under dash but can't get power to them. Any help would be greatly appreciated.
09-27-12, 05:04 PM
#2
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Check the fuse box right next to the battery not the one under the dash. In case of the battery crossing, The biggest fuse 120A Alternator is blown most of the case.
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WaveRunner (09-26-21)
09-28-12, 09:38 PM
#7
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You are well come.
Thanks for the report. I am glad that you find it.
Thanks for the report. I am glad that you find it.
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09-28-12, 10:38 PM
#8
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I think I'd better to write you one more advise, lex9856. You'd better to pay an attention on the slow battery leak when you had blown 120A Alternator fuse. The quick way to check this is to measure the current by an ampere meter or you simply wait weeks to notice the hidden slow leak problem.
The battery crossing causes too much current to the rectifying diodes in the alternator as a forward current. This is an extremely big current and the 120A Alternator fuse is quickly blown to minimize the problem. But it requires some mili-seconds to blow or open. During that short time period those 7 diodes in the alternator have that excess current too and the heat is generated and sometimes it damages some diodes.
They are not fully damaged but sometimes they cause a hidden leakage current problem. 
Depending on the situations and the reverse withstand voltage of the diodes, the leakage is sometimes very small or almost none and you can disregard it
but sometimes it is bigger and you will encounter the problem within a week or a month noticing that the engine doesn't start or the starting sound is weak.
As far as I know models 98 or after have a security system and the current from the battery is nearly 1A for about 40 seconds or so after you stop the car then shut the doors and locked. You have to measure the current waiting for nearly a minute at the battery terminal.
In my experience, most of the battery crossing was just needed to replace the blown fuse and you probably are OK. But for your safer ride, I suggest you to check the leak current.
The battery crossing causes too much current to the rectifying diodes in the alternator as a forward current. This is an extremely big current and the 120A Alternator fuse is quickly blown to minimize the problem. But it requires some mili-seconds to blow or open. During that short time period those 7 diodes in the alternator have that excess current too and the heat is generated and sometimes it damages some diodes.
They are not fully damaged but sometimes they cause a hidden leakage current problem. Depending on the situations and the reverse withstand voltage of the diodes, the leakage is sometimes very small or almost none and you can disregard it
but sometimes it is bigger and you will encounter the problem within a week or a month noticing that the engine doesn't start or the starting sound is weak.As far as I know models 98 or after have a security system and the current from the battery is nearly 1A for about 40 seconds or so after you stop the car then shut the doors and locked. You have to measure the current waiting for nearly a minute at the battery terminal.
In my experience, most of the battery crossing was just needed to replace the blown fuse and you probably are OK. But for your safer ride, I suggest you to check the leak current.
09-29-12, 04:57 AM
#10
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