A/c Fan Blower Went Out... Rx400H

[cduluk]

Hey guys,

This afternoon while driving the Rx400h, there was an instance where i smelled an "electrical burning" odor, but i thought it was just the car in front of me, and the smell passed quickly.

A few hours later i was in the car again, and noticed that i couldn't hear the A/C fan motor. I clicked on "climate control" and noticed it was set to "LOW" so i just thought that was why (i had the radio on at the time).

Well, tonight i started the car w/o the radio on and noticed i have no fan blower. No matter what i set the temp to, AC on or off, DUAL on or off, fan speed, zilch. I can hear the valves etc activating when i press buttons, but absolutely no fan blower.

I checked the fuses both under the hood and under the steering wheel area, and what do you know, fuse #65 "HEATER" with the description "electrical cooling fan, air conditioner system, rear window defogger, engine switch, windshield wiper de-icer" was burned out. I put in a new fuse and now it works.

I also noticed that the fuse #24 "RDI FAN NO.2" with the description "electrical cooling fan" was also burned out. I don't have any replacement fuses in this size so i'll have to buy one and replace it tomorrow. I have NO idea how long this fuse has been out or if it's related to the AC fan blower... And both of these fuses have "electrical cooling fan" in their descriptions. I'm just not sure what this means!

What do you guys think happened? Why would the fan blower fuse just blow out? Could the electrical burning smell i smelled earlier in the day be related? It was an "odd" smell...

Thanks for any input!

[lenore]

Hey you live in an area with lots of trees, maybe some leaves or debris got in the intake to the heating and cooling. Pull the air filter in the interior and see if you can see any debris below on the core. Maybe something got in there...Otherwise just chalk it up to a motor going bad or the speed control resister pack dying.

[RX400h]

C'mon, Luke, with all the dash dissassembly you've done over the years, you don't think a wire shorted somewhere? :chairshot:

Honestly, that'd be my first guess.

[SW03ES]

Yeah there's got to be a reason for the fuse blowing...

[lenore]

Hey guys,

This afternoon while driving the Rx400h, there was an instance where i smelled an "electrical burning" odor, but i thought it was just the car in front of me, and the smell passed quickly.

A few hours later i was in the car again, and noticed that i couldn't hear the A/C fan motor. I clicked on "climate control" and noticed it was set to "LOW" so i just thought that was why (i had the radio on at the time).

Well, tonight i started the car w/o the radio on and noticed i have no fan blower. No matter what i set the temp to, AC on or off, DUAL on or off, fan speed, zilch. I can hear the valves etc activating when i press buttons, but absolutely no fan blower.

I checked the fuses both under the hood and under the steering wheel area, and what do you know, fuse #65 "HEATER" with the description "electrical cooling fan, air conditioner system, rear window defogger, engine switch, windshield wiper de-icer" was burned out. I put in a new fuse and now it works.

I also noticed that the fuse #24 "RDI FAN NO.2" with the description "electrical cooling fan" was also burned out. I don't have any replacement fuses in this size so i'll have to buy one and replace it tomorrow. I have NO idea how long this fuse has been out or if it's related to the AC fan blower... And both of these fuses have "electrical cooling fan" in their descriptions. I'm just not sure what this means!

What do you guys think happened? Why would the fan blower fuse just blow out? Could the electrical burning smell i smelled earlier in the day be related? It was an "odd" smell...

Thanks for any input!

Funny when my electric cooling pump went on mine I also got that smell, turns out the fuse blew also....However the pump was bad, which caused the fuse to blow....You may be loosing your fan motor....time to price new one.

[cduluk]

Well, it's been a few days and everything seems to be back to normal.

I pulled the cabin air filter and felt around, but there wasn't anything in there. I'm thinking this issue has to do with whatever the "electrical cooling fan" is on this car, most likely something having to do with the hybrid system. I only say this because the only thing the two blown out fuses have in common is the phrase "electrical cooling fan". I think the AC fan blower went out because it "just happens" to be on the same circuit. Maybe to alert the driver that there's an issue with this "electrical cooling fan"?

Anyone have an idea as to what this thing might be? Maybe the fan that cools the hybrid battery?

I'm afraid that something might be "damaged" yet still working "now", and eventually die after my warranty runs out...

[lenore]

I think by the fuse that blew it is one of the cooling fans behind the radiator.....fuse #24 "RDI FAN NO.2"

[lemon]

Yes, radiator fan #2. If they are different fuses, I dont think they are on the same circuit.

Typically, the second radiator fan kicks in when extra cooling is needed, or the A/C is on. The extra air flow is needed to remove heat from the A/C condenser (which on the 400h, is sandwiched between the inverter radiator and the engine radiator - the inverter is first (closest to grill), then condenser, then engine radiator). When you're moving fast enough, the system stops the fans and let's the airflow do the cooling.

Wonder if your rad fan #2 fuse blew first for some reason, and then with the lack of airflow, the A/C system was working too hard, causing the A/C fuse to blow?

I would keep an eye on this since, as mentioned, those rad fans also cool the inverter radiator. Don't want your inverter overheating...

Fuse 15 is RDI fan #1 by the way. I think 'electric cooling fan' mentioned with fuse #65 is the blower for the climate control.

[cduluk]

Oh that makes sense... :(

I remember the exact moment when i smelled the "electrical" odor- i just got off of the highway after maybe a 20-30min drive, i was doing about 30mph in light traffic when i smelled it.

At first i thought the smell was coming from my gauge cluster, since a few days prior i replaced a few white LED's with red ones (which sometimes burn out if the voltages aren't right). Even though i did thorough testing before replacing them, it seemed ironic that this smell would occur within days of doing it. I even turned my dimmer switch down! But it wasn't that, the LED's were perfectly safe and not overloaded in the least. I'm 100% sure my work didn't cause this to happen.

There was an "older" car in front of me, so i just figured it was that. But if the smell was indeed due to the fuse going out, that's most likely when it happened. I don't remember what i had the AC set to, probably my usual of about 73 on the drivers side and 79 on the passengers side, with medium fan speed.

I really wish there was a way to find out why the cooling fan was shorted out. It wasn't raining out, conditions were normal, it was just a normal day. Really weird...

[lenore]

Have you turned on the AC to make sure the cooling fans are working? You have done a lot of Headlamp stuff too, Maybe the wire harness was disturbed near the fans, or maybe all said you just have a fan going bad...

[cduluk]

You have done a lot of Headlamp stuff too, Maybe the wire harness was disturbed near the fans...

HOLY CRAP. YES!!

On the same day this happened, the 28th, i saw a thread someone else posted on the forum claiming his headlights were out. I couldn't remember if a loose wire going to a single headlight would cause both to go out, so i removed the plug behind my drivers side headlight for a minute, so i could forward the message.

http://us.lexusownersclub.com/forums/index.php?showtopic=71536

I did have to "lift up" an adjacent fuse box (not the one containing either of the fuses that burned out) to gain access to behind the headlight... i did this around noon, a few hours before my drive when i smelled the burning odor... but the AC was working on the beginning of the trip when i smelled the "odor"...

Could it be coincidence? What could i have done? Where are these cooling fans, i can look around...

Good thinking lenore!

[lenore]

I would look closely at that area where you lifted wiring or fuse box. The fans are the ones mounted to the back side of radiator between the engine and radiator...

[cduluk]

hey guys, it's happened again.

This morning my A/C was working just fine. Parked it for a while, and when i got back in the car and after a few minutes of driving i realized the blower wasn't working. When i got home i checked the #65 fuse below the steering column and it was burned out. I put in a new one, and once i put the car in ACC it blew... Tried another fuse and it blew as well. Not only did the filaments in the fuses burn out, they "sparked" as bright as a match- actually enough to MELT the metal feet on each side of the fuses, creating little "beads" similar to those created during welding. All other fuses in the cabin and in the engine compartment were fine.

Took the car to the dealer and they spent a few hours looking for the problem. They came back stating they found the issue, "loose connection in junction block on D/S kick panel. Reconnected connector in junction block." They didn't charge me anything thankfully since we have an extended warranty.

I got in the car, started it up and the A/C and blower were working fine. However, about 5 minutes later on my way home from the dealer i noticed the blower stopped again. At this point the service dept had closed so i just went home. When i got home i checked the #65 fuse and it had blown again. Put in a new one, and just as before it blew out right away.

I guess i'll have to take it back on Monday! I have no idea what "connector" they're talking about, nor any idea how a loose connector could short out a circuit to the point where there's enough e- to MELT not only the filament in the fuse, but the feet on either side of it that make it snug in the fuse box. That's a LOT of electricity!

Any ideas? I haven't done anything to the car in a long, long while in terms of modifications... I haven't even cleaned it since we had snow on the ground (a few months...)

Anyways, while i was waiting for them to "fix" my car, i walked around the showroom. They had two new GS's, of course neither with the wood trim interior (which i'm trying to see in person), two RX's, two ES's, an IS, the IS-F, and the new CT. In my opinion the most beautiful car in there: '12 ES350 in truffle mica. I LOVE the side mouldings, chrome trim and especially the tail lights. I wish Lexus used some of these features on it's other models. I know "chrome" isn't as popular as it used to be, but i love it.

I honestly look forward to seeing it again on Monday when i take the RX400h back for this stupid blower motor... UGH.

[RX400h]

A "loose" live connection can touch a ground connection and generate some serious heat. If it weren't for the fuse, there may have been a fire. So remember, "shorts" blow fuses. There has to be + touching - somewhere in your car. Hopefully, it's somewhere accessible.

[jaswood]

I recently discovered that the entire area behind the P/S kick panel, SIDE kick panel was wet, VERY wet, multiple electrical connections, connectors, in that area resulting in numerous OBDII diagnostic monitor faults. Ended up being a problem with the windshield rubber sealing at the P/S right bottom corner.

Fixed the windshield seal problem but also wrapped those connectors with plastic just to be extra safe.

In the past I have had instances wherein long term exposure to moisture compromised electrical connections within a connector. Those "compromised" connections, especially connections carrying a fairly heavy electrical current load (12 volt source and grnd return most commonly) overheat, melting the connector plastic and now you might have 2 adjacent connections touching.

"..fuse spring feet melting.."

It is not altogether uncommon for these fuse holder spring (feet) to lose their "springiness" over a long period of time. Then you have less than a solid connection to the fuse ends. This is often the result of the circuit current flow be very near the maximum for a long period of operation, or in some cases the average current flow being well with tolerance but with surge spikes that are 10 times greater than the fuse rating. The fuel pump fuse/holder in the 77-88 Porsche 911 has become quite famous for this.

[lemon]

Ouch...did you check your sunroof drain tubes as well?

[RX400h]

but also wrapped those connectors with plastic just to be extra safe.

Wrapping the connector may allow moisture to be trapped inside. I would use a bit of dielectric grease inside the female connector to keep out moisture. This is what Honda does with their headlight connectors.

[cduluk]

I checked all the "connectors" behind the paneling down there and there's no moisture or anything that appears "out of place"- so i'm stumped. I dropped the car off at Lexus this morning and they put me in an IS250 loaner. I hope it's done tomorrow!

While we're on the subject, my loaner IS is a 2012 with ~5k miles, has nagivation yet no HID headlights... is it common for Lexus to give out loaners with NAV? I didn't even think you could get an IS250 without the telescoping steering wheel, auto-wipers and still get nav... very weird.

[jaswood]

but also wrapped those connectors with plastic just to be extra safe.

Wrapping the connector may allow moisture to be trapped inside. I would use a bit of dielectric grease inside the female connector to keep out moisture. This is what Honda does with their headlight connectors.

The top of the plastic "wrap" is tightly closed, tie-wrapped, around the wire harness to help prevent mositure entering the connector(s), while the bottom, below the connectors, is left "open". Kilt "like".

[RX400h]

Ah, that's better.

[cduluk]

Well Lexus has had the car since Monday (today's Thursday) and they called today to let me know it's fixed. I'm gonna pick it up tomorrow, as my IS loaner has been growing on me and the new car smell is addicting.

i'll update with what the cause was!

[lenore]

yes please post, we 400h folks want to hear anything that cause electrical to go haywire....

[cduluk]

yes please post, we 400h folks want to hear anything that cause electrical to go haywire....

Well they found the problem- a "chafed" wire which was lodged behind the dashboard, rubbing against grounded metal. They had to remove the entire glove compartment, dash, etc to get to it. Thankfully this time (a few years ago they had to remove the dash to replace the "white powder" issue in the evaporator core) they didn't scuff, scratch or chip anything. Dealer said it was covered under our extended warranty (couldn't they admit they broke something on the last repair?) and the final "bill" would have been $2.95 for parts and $960 for labor. YIKES... They did have the car from Monday to Thursday though.

In worse news, i discovered something quite "alarming" under the hood today... new thread to come.