Auxiliary Heater

[chrislloydie]

Been trying to get my auxiliary heater working properly. Originally, I found the fuse had been removed by the previous owner. After replacing the fuse and checking vcds for faults, the heater now starts up and runs with no smoke.

I have noticed that the run on pump is not working at all so I've ordered some new brushes to fit.

 

However, I think I've found the reason why the fuse had been removed. The heater comes on no matter what the outside temperature, I've had it come on with 19 degrees outside. The heater also runs constantly, even when the engine is up to temperature. This is a pain on long journeys and must affect the mpg.

 

So, anyone know why it's running like this? vcds lite is showing no errors. So I may just have to pull the fuse again.

[chrislloydie]

That should have been 13 degrees not 19 degrees.

[chrislloydie]

Hmm. Might have answered my own question. If the warm coolant is not being circulated to the aux heater, it'll still think the coolant is cold/warm and continue to run.

 

Still stumped on why it comes on above 10 degrees tho. Unless the temp sensor on the windscreen wiper arm is duff too!

[SilverBeast]

Someone may have taken the temperature sensor out and bridged the connections to force it to run at some point.  Or fitted a switch/link somewhere else in the system for the same purpose.

 

(i) Have you checked a sensor is fitted, not a link?

(ii) If fitted try disconnecting it to see if booster heater stops.

 

If coolant is not being circulated I would expect it to shut down anyway eventually as the internal senors in the auxiliary heater that record inlet and outlet temperature will still record a rise and I would have thought it would shut down with an overheat error anyway.

[chrislloydie]

I'll check for a sensor.

 

Definitely doesn't shut down, had it running even at end of an hours journey. No temperature lock out faults when hooked up to vcds.

[SilverBeast]

It would be worth getting a VAG_COM/VCDS-LITE lead from ebay (<

[chrislloydie]

I've got vcds lite. Scanned the aux heater and found no faults logged. Will have to investigate further by playing with vcds.

[orbis]

Now while this topic is on, it would be nice if you could answer a few little questions for me. I'm also busy with the aux heater on an MK2. I think it's easier to keep one topic about it at the time.

 

I removed the aux heater totally (coolant lines also disconnected), installed new glow plug, glow plug screen and new gaskets.

After I refitted the aux heater there was of course air in the system but it didn't disappear. Then I found out that the run on pump didn't work (I probably needs new busches).

I searched the fuse of the pump in Ford-TIS and it was Fuse 9 (5A) (at least I think it's that fuse). Then I saw that there was no fuse 9 so I refitted one.

But With or without fuse 9, there keeps going power to the pump.

When i pushed hard against the connector , the pump did work, but the air in the system didn't disappear and the level in the coolant tank didn't lower.

 So now i'm going to replace the brushes in the motor of the run on pump.

 

Questions:

1) What is fuse 9 for and what is the right fuse for the run on pump?

2) how can I get the air out of the system?

 

Many thanks ;)