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93 ls400- Electrical Knocking????

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Old 07-09-11, 07:28 AM
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vicious
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Default 93 ls400- Electrical Knocking????

so i started it up and i got this knocking sound, and it was knocking in a pattern (4-5 knocks, silent, repeat). so i turned off the car and just turned on the electrical components and the knocking started up again.. any ideas???

problem may have started after i pounded the dash to get my needles working

Last edited by vicious; 07-09-11 at 07:53 AM.
Old 07-09-11, 07:37 AM
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steve2006
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Could you be a little more specific for example where is the knocking sound coming from front or rear? If the front have you lifted the hood got someone to turn on the ignition and had a listen for the location of the noise?
At the moment it could be someone locked in the trunk trying to get out.
Old 07-09-11, 07:45 AM
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vicious
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Originally Posted by steve2006
Could you be a little more specific for example where is the knocking sound coming from front or rear? If the front have you lifted the hood got someone to turn on the ignition and had a listen for the location of the noise?
At the moment it could be someone locked in the trunk trying to get out.
naw i made sure she was knocked ouah.. i mean... lol

it sounds like its near the drivers side air vent next (by the pedal). thats where im feeling the most vibration from the knocking

its def somewhere under my dash

Last edited by vicious; 07-09-11 at 07:54 AM.
Old 07-09-11, 08:08 AM
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deanshark
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It sounds like it might be on your heater assembly, one of the gears that opens the doors for the vents might have a tooth missing or the servo motor could be stuck to run constantly. There's alot of servo motors on the assembly to adjust the air flow through all the different ducts. Try setting your HVAC to defrost (windshield), then heat (feet), then vents, all the different settings.
Old 07-09-11, 12:37 PM
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vicious
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its def coming from the heater assembly.. anyone know how to get to it??? already have the whole radio console removed but dont know how to open up that white box behind it
Old 07-09-11, 12:54 PM
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Hilux22RE
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To Get to the heater assembly where the heater core and vents are located the whole dash must come out. Its a PITA..
Old 07-09-11, 12:55 PM
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Hilux22RE
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https://www.clublexus.com/forums/ls4...d-removal.html

Check this out.
Old 07-09-11, 01:52 PM
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vicious
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thanks for the help

saw somewhere on here talk about coolant so looked at the reservoir and saw it was low. filled it back up, unplugged the climate control (no noise when it was unplugged) plugged it back in, turned it on and the noise was gone.. not sure if it was the coolant or the climate control unit but at least its gone
Old 07-10-11, 08:27 AM
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deanshark
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Originally Posted by vicious
its def coming from the heater assembly.. anyone know how to get to it??? already have the whole radio console removed but dont know how to open up that white box behind it
Just for reference if anyone searches and asks this question in the future, "how to get the heater assembly out and open", the link above shows some of it but this is my link when I took it out. Post #7 tells what needs to come out.
https://www.clublexus.com/forums/ls4...ater-core.html
vicious; good that it's not making the noise anymore, it might have just been some wires or something rubbing against the bar which moves the doors for the vent which you got out of the way when you took out the HVAC controls.
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