additude

My LS has a single in front electric radiator fan located on passenger side. The engine has a single clutch fan located behind the radiator off the water pump. I have never witnessed the electric fan turning.
I don't know if it is an RDI fan or an A/C fan.
The fuse box shows a diagram under the lid 30A RDI FAN and there is a good 30A fuse in that location. The diagram under the lid is not "/" out.
Does any one know for sure if this is an RDI FAN or an A/C fan or how I can positively identify the fan function?
I have owned the car for 17 years, I've never seen this fan work in any way.
I am under the hood frequently.
I don't know what to troubleshoot, RDI Fan?
Thanks.

fastegg

Hi additude. On my '99 LS400 the electric fan is for air con and comes on when you turn the air con on. It is also a back up fan if the engine overheats (about 100 degrees C).... Also, I took my engine fan off and fitted a 16" thermo fan. Apart from making the whole engine much quieter, I got about a MINIMUM 10% improvement in fuel economy. And by the way, the thermo never comes on unless your in bad stop start traffic... Where I live there is rarely any traffic so I would say it comes on maybe once a month and only for a minute. Best money I ever spent.

fastegg

By the way... What's an RDI fan ?

additude

Hi fastegg,
Thanks for the reply. I sort of thought the same thing, that it was an A/C related fan. But because the Fuse Box cover doesn't have a square symbol with a slash thru it like I've seen in other pictures, I'm just not sure.
My front electric fan is not on when the cabin Air Conditioner is on.
Do you happen to know the fuse and relay, associated with the A/C on/off circuit?
Maybe I could troubleshoot from that...
As far as I know, RDI means Radiator Fan.
Thanks.

fastegg

No idea of circuits and relays sorry....

timmy0tool

iTrader: (7)

start with the relay/fuse box in the engine bay and check for blown fuses. it may just be as simple as that. then check the under-dash fuse box as well.
then check the relays afterwards for proper function.

additude

So I tried something I read about that an RX300 guy did and I was able to make the fan work.
I tried it several times but this was the most consistent way I found to make the fan work normally.
1. Start a cold car
2. Place the A/C on lowest temperature and cabin fan on high
3. Roll down two windows or leave the door open to defeat the A/C cooling
4. Watch the RDI or Condenser fan and about the time the engine starts warming and begins to idle down
5. The RDI or Condenser fan will turn on automatically

timmy0tool

iTrader: (7)

that is how the fan should work normally when the temp reaches a certain degree. it's not always 100% on when the AC is on (such as when driving around town and the front of the car gets ample air flow).
sounds like you just didn't wait long enough in the beginning, or the car wasn't up to temp.

fastegg

Interesting... My AC fan seems to run all the time when the AC is on....