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Blake_batonrouge

Rpm Gauge And Electrical Issue

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Hey guys,

I have 2 questions:

1) When I turn off my car, the RPM needle drops down past "0" and rests on the bottom of my cluster. Also under heavy acceleration the needle tends to be slightly irratic and sorta sticks for a moment before it comes to back down to the correct rpm. Is this normal?

2) I replaced my power antenna mast last week, I am noticing on certain presets, the antenna goes up and down slightly. I checked the manual and could not find anything on this. Is it some sort of electrical short?

3) I have also noticed that my a/c conditioner shuts the fan off completely at diffrent times. The unit remains functional but the fan seems to cut off, and I have to change temp to get it to come back on. Is this normal?

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1. Doesn't sound normal.

2. LS's antenna's do that for some reason, I'm guessing for better reception. I like it ;) haha

3. No idea. Haven't used A/C in WA for a loooong time lol. :lol:

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You have a cluster short,

the antenna is supposed to do that on all Lexus models

which fan hvac for the vents or rad

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clean the sensor on the lower dash under the ignition. It has 3 slots for its opening.

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clean the sensor on the lower dash under the ignition. It has 3 slots for its opening.

Anyone got a pic of this?

I am still looking for the sensor and I can't find it. Can someone point me in the right direction.

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I am still looking for the sensor and I can't find it. Can someone point me in the right direction.
It's the little square opening about an inch above the top of the gas pedal in this pic...

N0139168-17sm.jpg

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Hey guys,

I have 2 questions:

1) When I turn off my car, the RPM needle drops down past "0" and rests on the bottom of my cluster. Also under heavy acceleration the needle tends to be slightly irratic and sorta sticks for a moment before it comes to back down to the correct rpm. Is this normal?

2) I replaced my power antenna mast last week, I am noticing on certain presets, the antenna goes up and down slightly. I checked the manual and could not find anything on this. Is it some sort of electrical short?

3) I have also noticed that my a/c conditioner shuts the fan off completely at diffrent times. The unit remains functional but the fan seems to cut off, and I have to change temp to get it to come back on. Is this normal?

1) reseat the connections to the engine control ECU.

2) SOP, higher FM frequencies use a shorter antenna for increased reception.

3)...At initial engine startup the blower motor is programmed to not come on until the evaporator core temperature is low enough to provide at least some level of cooling for the incoming airstream. Other than that I don't know of any time the blower will be completely shut down. VERY low speed, QUIET speed, but not shut down.

Oh, some of the later LS models would shut off the blower, or at least lower the speed significantly, if the captive cell phone rang or was in use.

Maybe if the evaporator temperature rises back up to a higher temperature for some reason..??

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Okay, I think I figured out the on and off ventalation fan issue. When i went to lunch I started the car and let the A/C run. This is what I noticed. Once the car gets to the set temp, it turns off the fan completely. When I opened the windows and let the hot air (90 degrees out today) into the car, the fan came right back on and cooled the car off. Once it reached the temp again the fan turned off. Maybe this is just part of the system, but I can't find any documentation in the owners manual about the situation. Also, where are the ECU wires that effect the PRM gauge?

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Okay, I think I figured out the on and off ventalation fan issue. When i went to lunch I started the car and let the A/C run. This is what I noticed. Once the car gets to the set temp, it turns off the fan completely.

Completely off...?? You're sure...??

Is the blower indication still on and at the low speed setting...??

The blower is very quiet, VERY quiet at the lwest speed.

When I opened the windows and let the hot air (90 degrees out today) into the car, the fan came right back on and cooled the car off. Once it reached the temp again the fan turned off. Maybe this is just part of the system, but I can't find any documentation in the owners manual about the situation. Also, where are the ECU wires that effect the PRM gauge?

...

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Thats your coulprit then.... you have auto climate on.. which means it controlls the temperature automatically... turns the fans on and off, higher and lower..

It will also crank the fans up more once the car warms up! ;)

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I always leave it in auto and let the system do the rest. Jcrome where is the ECU connection for fixing the RPM gauge?

wwest is right on the money and there is no ecu conn. or what not ,read my post on dead tach.let me know.and you succeeded in figuring out the a/c problem.

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