with the winter rain in cali i really need my heater to clean up my fog up view. does anyone know the problem. 86 rx7 na

try a new thremostat

always found ac to get rid of fog quicker..

in the cold? ive never even though of using it outside of the summer not that i have it any ways lol

yea i feel da ac do kills fog faster but mine is mess up too

ive searched online and most points at the logicon. you knoe anything about that ??

Yes the ac does remove fog faster. Thats because it blows the air through the evaporater first, which pulls the moisture out of the air before blowing it onto the windshield. Anyone ever notice that on newer cars the AC compressor kicks on when you turn on the defogger?

imported cars started the seperate AC button as far as I can remember.

Before that you just clicked the defroster on or the AC and did not have a seperate AC switch.



No matter how good your heat works if your ac does not work your windows will not clear up as good.

I think he was more asking WTF is wrong with his heater.

whats the problem with the heater would be a good place to start.



just saying "heater problem" is rather vague, i run into tons of different heater problems everyday at work.



does your car reach proper operating temperature, is your coolant completely filled with no air bubbles, does your blower motor/fan work on any/all speeds, is your thermostat original, have you flushed your coolant recently, does air come out the defroster vents or does nothing happen when you set it to defrost mode.



i can keep going....



kevin.

my bad fellas but i do get air out and it works at all speed when i turn on the ac the car's edle goes down den die and the heater dont work at all.

did dat sound better

I probably have the same problem as you nATZ, I have a new thermostat, water pump, the coolants full (no bubbles), air comes out the defrost vents (or other vents as selected), and at all speeds selected but the air isnt warm (no heat so no defrost), I was thinking in my case (and possibly yours) that the heater core is plugged or whatever allows water to go into the heater core wasnt opening properly what do you guys think....



it might take some time infront of the chiltons, and some research under the hood, but I'll keep ya posted as to what I find out

yea dats how mine is wut about your ac does it work to ?? when i turn mine on idle drops and car dies

there is a switch type thing thats supposed to kick the idle up when you put the ac on.

Also if there is no refrigirant in the system it will not work, you need to see if the compressor runs when you flip the switch.



There is also a pressure switch i on the hard line that runs from the compressor to the condensor in the front of the car, it has 2 wires coming off it, its cheap to replace as well.

yea in hillbilly's case id start by making sure coolant can flow through your heater core (detach the inlet and outlet hose, attach garden hose to inlet, turn on garden hose, water should come gushing out of the outlet hose...if not its clogged)



also i think one of the coolant sensors has a play in the heat.



and the logicon is known to go bad, not too hard to find an s4 one, s5 is a bit more work to find.



kevin.

Mine has this same problem, the air mix motor on the drivers side of the heater core is bad. crawl under there disconnect the arm on it and flip it the other way. If you want to replace the motor you will have to pull the dash.





Now I have a question, I know my air mix motor is bad, but when you select another postion for the vents they dont move, would me logicon be bad or would it be the motor on the pass side?

does da compressor work if the ac does gets cold but i have to keep my foot on the gas to keep my car from turning off??

yes the compressor works, the thing for the idle is not.



I dont even remember what its called, it acts up sometimes on my car where the car will die when I come to a stop.



Is there any smell in the car when you run the defroster?

I believe the bypass air control valve (BACV) is responsible for kicking up the idle when the ac comes on.

yea the BAC kicks up the idle, take it off, carb clean it, slap it on, make sure the connection is still good. on car's nowadays its called the IAC.



fc3s4u - there are seperate motors that control the HVAC "doors" sometimes they stick or get stuck by objects. Basically you'll probably have to pull the dash to get a guaranteed diagnosis on it.



kevin.

thats what i was affraid of, Ohhhhh well I guess it will be broke then.

ok i will try dat i will remove the BAC then clean ill keep u guys updated thanks

does the air only come out the passenger floor?



if so the box with the a/c core unit in it (sometimes people remove them to FULLY remove the a/c system) might be cracked, or the straps might be loose or missing, have this problem on my FD and my T2. on the t2 its cause i cant get it to line up right on my fd its cause the jackhole before me lost the straps.



anyway that box is where the air passes through before it gets to the doors so if its leaking out of there then it would never reach the doors.



kevin.

No its like the flapper is stuck in there, it only has dash vents. And it sucks in AR as much as it rains down here, windows fog up really bad. I might see on my days off this week if I can take that speaker out and see anything, I have a complete heater core box with all the motors on it if I nd them.