2000 Ls 400. Front Defroster Not Blowing Very Much Air

[max22max]

It does change modes from floor to dash to defroster. But when it is on defroster I can barely fell a little bit of air coming out the defroster . I hear lots of air blowing under the dash. Seems the vents might need to put out a little more air But not sure?

[1990LS400]

The key question ... is your defroster working well enough to defrost your windshield?

I went through 11 winters with a 2000 LS400 with a significant portion of my winter driving being in almost to the southern border of Minnesota. It's defroster worked well enough the majority of the time but sometimes not well enough to melt accumulating ice when driving in freezing drizzle - I pulled off Interstate highways numerous times on long trips to scrape ice from the windshield and to free up the wipers. I sometimes had to manually set the fan speed and temperature to maximum. My 1990 LS400 defrosters performed about the same in this respect.

I did a "happy dance" when I found out that my Toyota van has an electrically heated windshield ... would have bought it anyway but it was a nice bonus.

[max22max]

not ice and snow I am worried about rite now. This one wont even keep the fog off the inside on a rainy day. thanks though

[Exhaustgases]

I know nothing about that year car. But I am sure it has the climate control diagnostic just like the older ones do. That is where I would start, it should check servo motor action etc. it sounds like the valve for that function is not working correctly.

Also didn't they have cabin filters on those years? Make sure its clean too.

[Clunkfish]

Also didn't they have cabin filters on those years? Make sure its clean too.

I second that. When I replaced my cabin filter the air flow increased very noticeably. You can find it behind the glove compartment: there's some very helpful info here http://us.lexusownersclub.com/forums/topic/34808-how-to-replace-cabin-air-filter/

[1990LS400]

not ice and snow I am worried about rite now. This one wont even keep the fog off the inside on a rainy day. thanks though

Well it certainly should be removing condensation on the inside of the windshield. Is the A/C working OK? The A/C should turn on automatically when the front defroster button is pressed unless someone has changed the "COMPRESSOR/DEFROSTER/OPERATION" setting to "NORMAL" with a scan tool. "LINK" is the default setting.

Like others are saying, the cabin filter could be blocked but that would be affecting all HVAC modes - not just defrost. I've seen some hilarious photos of cabin filters that have never been cleaned or changed - totally blocked. I sometimes cleaned the filter with compressed air between services at which time my mechanic would change it.

Be gentle when removing the cabin filter as some have damaged the little door in front of it - an expensive repair.

But really ... there was never seemed to be a lot of air flow from the defroster vents in either of my LS400's but it was plenty enough to quickly clear condensation.

[max22max]

Well thanks everyone. I took the cabin filter out yesterday evening. It looked terrible. I have a new one ordered. I really think that is the problem. I will know in about a week when the new one arrives . Thanks to all.