I can't seem to get my heat to come on in my 1993 sc400, but the A/C works just fine. It does not even blow when I put it on 75F or higher. Does anyone have a clue?

 

I had a similar problem with my 92 sc3. A/C worked fine, all the vent settings were working properly, but no hot air. Took it to the dealer and they replaced the the Magnet Valve assy (p/n 8869024060). I'm not sure if this is the same as yours. Fortunately they replaced it under warranty (list price $255 part and 1 hr labor).

Good luck!

 

A couple of years ago my car did this exact thing. A foreign car mechanic name Bob Mitchell fixed this in my car for $35.00. He said that a valve/door was not opening properly. It only took him about 30 minutes to fix!

I'm not sure what he did, but it was a cheap fix and the heat has been working find ever since!!!

 

I have a similar problem but with a little twist:

Heat works fine and blows fine untill I come to a stop and the car is at idle. Then she blows cooler air. Light turns green - I go - and the car spits out hot air. Can't seem to figure it out. A couple of times, the heat did not work at alll, but it kind of switches between not working at all to only working when driving.

Personally I don't care; I live in florida and have only needed to use the heat on several occasions since I've ever even owned the car (~5 yrs).

 

Have you had your radio taken out/serviced recently? Did you notice this problem after that?

I noticed inconsistent heat from mine, and had a lengthy discussion with my Lexus dealer. He suggested I look at the vent to the right of the steering column, next to the key. It's a vent with several slots, about 1" x 1". It is what reads the temperature and determines what to push out of the vents.

He asked me the same question, and I said "YES!!!". He theorized that the tube going to/coming from the vent might have a kink in it. Since this problem is intermittent, I have not yet looked under there, but he seemed confident that (given the radio work) it might be this.

Just a thought...hope this helps!

 

I had this exact problem and fixed it by filling the coolant reservoir. They crack and leak and will only hold a small amount of fluid. The car would not overheat but it also would not heat... hmmm..

I got a new reservoir, filled it up and the heat has worked ever since. If the air is cool or stops when you slow down, this is the cause. Not enough coolant is circulating so the heater does not work which is kinda ironic huh?

Anyway, fill the reservoir with distilled water to the very top while the car is running and if the heat works, this is the cause.

P.S. Don't even try re-sealing the reservoir, I tried everything and steam bubbled through every time. And oh yea, the reservoir is 150 to 250 bucks.

 

I havent had dash or radio work done prior to this problem, but I will check that hose out for a possibility. I will also check the coolant level and look for leaks/cracks, but I most definately will top it off and try that route.

Thanks, people, for the info. Hopefully I will get this solved and post the results. Thanks again. I'm sure fixing the heat will keep the lil' lady happy when she rides in my car since she started complaining about how nice cars shouldn't have problems like this.

Keith

 

Funny: Whenever I do have a problem with my car (keep in mind, it's almost a decade old with 114,000 miles!!!) people (family) say "What's wrong with your TOYOTA?".

lol...they think it's some type of dig, that it will elicit some type of emotional response. I just laugh...the only other car almost that old in the family is falling apart, is on its second transmission, and feels like it will fall apart if you take a turn too hard. It is a Mercury Sable, a popular car, probably great to lease or own and trade in after 4 years, but not for keeps forever like my Lex!

Long live the Toyota!!!

 

Yeah, I get the same comments. So what? It is made by Toyota and the lexus coupe rocks. Yeah buddy.

 

Yeah, but I hate the :

<insert whining, high pitched, annoying voice>

"You spent all this money on a so called quallity car and everything is broken on it........my friend has a Ford Taurus (pinto, or whatever POS car) and it doesn't have half the problems and they only spent $2,000 for the whole car".

I never hear the end of the torn leather on the drivers seat, heating problem, and a power seat switch that went out (but was fixed by cleaning the contacts). These simple problems have put the shadow over my car, and now her whole family thinks that Lexus' are junky, overpriced cars, that break down.

My A/C compressor locked up and froze and I never heard the end of the $2,200 bill for that. Now my car is a "never ending money pit". Considering that nothing has costed money besides normal maintenence before the A/C problem.....I think pushing over 6 digits on the odometer without a single problem is proof that Lexus' are very reliable dependable cars. Ocassional problems are expected, but in their eyes - expensive cars; I guess, are meant to be perfect.............women!!!!!

Anyway, I'll step off the soap box now


Keith

 

I'm going to try all of the things that you all said and see what happens.

 

Once again....my old Fiero steps up to the plate....

I had a water pump that was bad...when I was at idle...it wasn't moving enough water....and the heat would get cold. Once I started going....pump sped up, heater got warm again. You might wanna get that checked!

Sable? I had an 88 sable. What a POS. 69k miles, the auto tranny went out! We put in a 4.6 V8 and the tranny from a Buick Rivera with a custom bellhouse. That was fun...

OF COURSE a car that was $60k new, that now costs 10k should NEVER have a problem and should run until at LEAST 500k miles. What else would you expect?!?! (ya...lets see a sable with 500k on it...maybe if the odometer broke and started rolling 100's instead of 1's)

SR