Condensed Water On Ac Pipes, Why?

RX300MS · October 23, 2009

Guys, I had problem with my blower fan where it comes on and off intermittently. I suspected it's the relay but i was not able to find a replacement.

Lately I am smelling rubber burnt after stopping the car. Both fans are not running when I parked the car. I tested the two cooling fans in the front by providing 12V power, they all work.

My question is when should the fans come up? I think one is for AC so it's not supposed to come on if AC is off. But what I am seeing now is when i start the car, and let it idle a few minutes, none will come on. If I turn on the AC, both fans run. And I am seeing water condensed on the AC pipes under the hood.

Can you guys give me some ideas on what this could be? If the blower is not working, will that cause the condensation?

Thanks so much!!

code58 · October 24, 2009

Guys, I had problem with my blower fan where it comes on and off intermittently. I suspected it's the relay but i was not able to find a replacement.
Lately I am smelling rubber burnt after stopping the car. Both fans are not running when I parked the car. I tested the two cooling fans in the front by providing 12V power, they all work.

My question is when should the fans come up? I think one is for AC so it's not supposed to come on if AC is off. But what I am seeing now is when i start the car, and let it idle a few minutes, none will come on. If I turn on the AC, both fans run. And I am seeing water condensed on the AC pipes under the hood.

Can you guys give me some ideas on what this could be? If the blower is not working, will that cause the condensation?

Thanks so much!!

RX300MS- Looks like you've been around since '03 but this is your 1st post? I assure you that most of the time you'll get a better response if you at least fill in the information on your vehicle. Often, regulars won't bother to respond when they have NO information on the vehicle to go on. You say you suspect it's the relay but weren't able to locate 1. Where did you try? We don't even know if you live in Alaska or the Congo. Have you tried the Lexus dealer? The cooling fans are only going to come on if the A/C is on or the temp is high enough to call for cooling and most fans (engine) don't run for very long before they shut off unless it's a hot summer day. When you start the car and let it idle, none are going to come on unless it gets warm enough. If you are in Minnesota this time of year, your fan may never come on because it doesn't NEED to. When you turn the A/C on (this is a different circuit), both fans are supposed to come on and the condensation is completely normal. When the A/C is on, the pipes will either be frosted or condensation, that's what they do. The A/C also automatically comes on whenever you use the defrost because that's the way it's wired.

RX300MS · October 24, 2009

Thanks Code58. Sorry I did not provide enough info, I have a 99 RX300. I didn't go to dealers, don't want to be robbed off. I only tried ebay. I was hoping to get a used one there. Thanks for your info about fan and AC, that cleared my mind. And I am in GA.

I was suspecting that the smell comes from something being too hot b/c of the fan not coming on. I guess I still need to do some research to find out why now.

BTW, I don't believe this is my first post though :)

code58 · October 25, 2009

Thanks Code58. Sorry I did not provide enough info, I have a 99 RX300. I didn't go to dealers, don't want to be robbed off. I only tried ebay. I was hoping to get a used one there. Thanks for your info about fan and AC, that cleared my mind. And I am in GA.
I was suspecting that the smell comes from something being too hot b/c of the fan not coming on. I guess I still need to do some research to find out why now.

BTW, I don't believe this is my first post though :)

Sorry about that RX300MS :blushing: How to embarrass yourself: look at the post count in the upper right corner rather than in your profile. I am not sure what they use for a relay. Is it a Lexus only part? Do you have any "Pick-A-Part's" in your area? That's where you go and take the part off yourself and it's MUCH cheaper that a regular wrecking yard. I don't blame you for not wanting to go to the dealer. When a car gets that old, the aftermarket sometimes even supplies them because people aren't so inclined to go to the dealer for parts then. Good Luck!