I was about to find out why the PTC or pre-heater has been throwing codes. With colder weather not far around the corner , I began with taking the side panel off to see if the heater plugs had power. I turned controls to full heat and while increasing the fan speed to maximum , there was water pouring out from around the top of the PTC unit. I thought the unit was , well it is electric. with the large cables to it either footwell. So how do I get water there when it's never ever appeared before. The only thing I did was to remove the small plug beside the large earth to test for power, this I did by running the car with heater control at maximum. I understand this is the way it comes on if normal water temp from engine is not there. .



The water looks clear , so if controls are on hot , it can't be aircon or is it? Help very much appreciated.

Ignore the crash input on diagnostic pic., was there when I got the car, not sure if I can erase that.

this hopefully the video I took: ok doesn't look like it uploads videos.

I wonder if its air con water
I have read the PTC comes on when the Prog button is pressed. It in fact comes on automatically when the ambient temperature is at 5 deg C. It can't be switched on with the prog button unless someone can tell me differently.

What are you live values for the PTC

I will have another look at live values , I thought I tried looking for them the last time I was using GAP.So will have another look . I think I found the drain tube for aircon water on the drivers side, a rubber tube that disappears in the centre tunnel down the side. So I went underneath to see the outlet and couldn't find it, I assume that its behind the protection running along the underside of the tunnel. It could possibly be blocked. Yes PTC switches on by putting heat settings to full on. From what you say to whatever the outside temp is doing.More investigations.

I had water coming into mine and soaking the carpets because the end of the plastic tray that runs under the windscreen to collect rain water was blocked with leaves etc where the little flaps are at either end, I’ve never had the problem since as I make sure they are clear whenever I wash the car. 64 plate TD4 SE Santorini Black
2021 Mazda MX5 GT Sport Tech

There’s a hole in the round rubber thing in the plastic under the screen too. Yes it’s amazing how much rubbish collects in those rubber flap things.

Yes checked screen , seem OK.
In reply to live values on PTC ,I can't see anything related or saying PTC on GAP. Maybe called something else, enlighten me if possible ,please

Looking up the code I entered earlier in this thread U2101-00, says Fuel Fired booster heater not configured. There is more but the car does not a have a fuel fired heater, odd! Sorry thats a new code , which will not clear.

So the original does sy that the PTC Positive temperature
coefficient heater circuit -
short to ground, open
circuit
I assume its broken then.
Anyone changed this the PTC.

Yes the Fuel Fired heater shows up on all my code readers but it's not fitted.

I had a temperature value show on my GAP reader for the PTC but it's not showing currently I wonder if it only shows when it switches on at 5C, Will have to wait and see. There is Youtube Movie on the thing.

yes , been following it. I think your right on temperature activation.
Will check on a colder day now.
I wonder if by removing the centre console I might spot where this water might be from , such a PITA to get at , but then a lot of these heaters on other cars are the same. Thanks for your input.

There is a new movie on the side drains

Amazing, because I have subscribed to this guy , I have had it through notifications, but thanks , will investigate.

Amazing, because I have subscribed to this guy , I have had it through notifications, but thanks , will investigate.

Sorry sent twice!

alfapat wrote:

Amazing, because I have subscribed to this guy , I have had it through notifications, but thanks , will investigate.