So a month ago I'm driving home in my 1989 Japan spec TT. Lovely and warm with the heater blowing into the cabin in ECON mode. The windscreen starts to fog up so I click the front windscreen defroster (that starts the A/C automatically). Once demisted I put the climate control back into AUTO which I have done a thousand times before - and no heat. For the next 4 weeks, no heat just ambient temperature air. Bloody freezing at 6:30 in the morning ! I search for hours on the AU/UK/US forums for a possible solution. I run the climate control diagnostics, everything is fine. There is no coolant leak in the cabin, the floor, cabin and windscreen vents all work. I end up spending half a day flushing the coolant in the radiator and engine, till the water is running clear - it was a lovely brown colour. During the flushing process I had the climate control on and set to 40 to make sure the heater tap was open! The engine thermostat was opening and closing correctly. Topped up with coolant but still cold air. Kept parking the car on an incline (nose up to get air locks out) at night and topping up coolant in the radiator and reservoir in the morning. Nothing still cold air. Pulled the vents under the steering wheel and cleaned the little green sensor in back vent. Its a manual so couldn't go any further without removing the clutch pedal. Still cold air. Last night (a week later) driving home with 4 layers of clothing on and gloves ! I feel warm air coming from the cabin vents above the radio. I click the AUTO button and ECON - and lovely hot air circulates the cabin !!!!!!!! This morning drove into work again lovely hot air - it fixed itself???????? Was there possibly a blockage in the heater core that eventually cleared 2 weeks after the coolant flush? Your thoughts please? I am so happy as I was looking at a dash out fix that would have been a nightmare because nothing seemed wrong except no hot air coming out !!!!! Cheers
May have just neglected to type it in, but for the 4 weeks, while you just had it in AUTO mode, with no hot air, did you also have it in ECON mode?
Mate I tried every combination possible. When it started working again I had been driving for 30 mins with the climate control off suddenly I could feel hot air coming through the cabin vents.
Probably a stuck directional flap. Stopping the flow of air in the directions youre wanting. They can get stuck due to grime or leaves, etc and youre left with it up on the windscreen, or midway between. Our old red zed used to do this periodically. Always fixed itself eventually.
Blocked core or bubbles?? Hahahah nope!! However, my system, and a few others, I have read about have this strange behaviour where they either fry you or freeze you. Seems the air mix doors either stick or the servo motor sticks or the ECU gets confused. This always happens when Im running mine in ECON mode. Mine usually fries you but still occasionally freezes. I dont ever recall it playing up when AC is running. What seems to fix it is in AUTO mode, to DE-select ECON (AC on) and run the temp up to full blast for a bit, let it have a good think about things, then run the control all the way to minimum temp and let it run there for a bit to contemplate its future. Sometimes takes a couple of cycles but always seems to sort itself out and might not misbehave then for months on end. Ive not bothered much to investigate why and just cycle it every now and again. One day. E
That's interesting you mention the ecu. A week prior to the heat stopping I had the stock chip upgraded to a czp because I had 550cc injectors installed. Coincidence? The heater was working after the upgrade though.
Oh, sry, I should have been more specific, the AC cyctem has its oow ECU and thats what i was referring to. Im guessing your issue is coincidental!!!! E
No apology required. Thanks for your advice I'll definitely give it a try if and when the climate control goes belly up again. I'm on an Android phone and I can't see the 'thanks' button
see how you go m8. That "fix' has been written about several times. I actually had to do it myself last weekend to get the zed heater happening the way i like it!!! E
