So as the title says, my heater does not work.
i have changed the thermostat,
i have not yet checked the motor brushes to see if it working or not.
one thing i did notice today when looking is it seems to me there is no power going to the heater control valve.
i turned the heater on to full blast, and then disconnected the plug that runs to the heater control valve and connected a globe as a test light (cannot find my multimeter) and the light does not come on, indicating to me there is no power going to the circuit. and therefore the valve is not getting the signal to open.
what could be the cause of this?

 

Spud!

You have self-defeated. A full-blast variable heater valve (meaning fully open) does not need any voltage to be open! It needs a voltage to close. So close it (put temp at LO) and you should get a globe glow. A problem here would be rare.

The not-rare problem is worn-out motor brushes. Whack that dead motor and it might come on. Most who have disassembled the motor have found toasted brushes. I've seen on the forum here how they can be replaced, although I have not had to do this in the land of 115 degrees F.

I occasionally complain about the heater valve staying open when the engine is shut off (zero volts). That allows the coolant in the matrix to heat-soak. Upon hot-start, the A/C vents will blast hot moist air until the A/C overcomes. It is annoying. But I'm not complaining right now, my A/C works well.

 

Haha thanks.
as my name suggests, i am infact a spud. A massive spud.
you are correct i put it to cold and yep. Light comes on.
i was feeling the hose on the exit of the valve and it was cold so i disconnected the hose and hot coolant comes out the valve. So yep it is open.

i have tried before and tried again now, bash the heater pump motor and nothing happens,
checked all fuses and they are all good.
i did just disconnect the heater pump relay (3rd one in near the air box) when i disconnected and reconnected it i did not hear any clicking coming from the relay activating. So the relay may be busted.
i really need to find my multimeter or just go and buy a new one.

 

I'm not sure about the AU slang, I hope Spud isn't too derogatory! In the US it would be considered a funny but harmless word that I know of to be UK speak for "potato". Mr Potato Head is quite well loved here.

 

exactly how it is used here.
i live mr potato head. Lol.
me and the missus actually have nicknamed each other spud. Lol
🥔🥔🥔🥔🥔🥔🥔🥔🥔

 

How romantic! Lol. Made for each other. You know you can do a lot with spuds! I suppose there are worse nicknames.

 

Ok so,
i swapped out the relay with a known working relay and still did not hear it clicking at any point.
i unplugged the relay and bridged the terminals with test light and there is power into the circuit.

but still the heater pump motor does not engage so i can only assume it needs repair.

my other question tho is when i turn on the heater i am not feeling much air (if any at all) blowing through the dash vents. It is blowing strong through the windscreen vent but not through any other vents.

when i turn the ac on and down nice and cold i get decent cold air blowing through the vents but turning the heat on is not getting me much (if any) air at all.
not hot nor cold air.
is this a symptom of the heater pump motor not working or something else?
i would have though if the heater pump not working when i turn the heater on i would get cold air blowing through. No air makes me think something with blower or vent servos or something also.
but i really have no idea.
climate control systems are new to me.

 

Seems like the new relay should click when engaging the heat. Wire the motor directly to power to test it. Next step:

 

Will have to get to it next weekend now.
no time left now today. hopefully i can make some progress on it next week.
it does have me baffled at this point why the relay does not click on. hopefully its not the control module.

but yeah will check the motor next and am expecting to have to replace the brushes.

 

question....

given that i am only really feeling air blowing through windscreen vent not through the dash vents at all is it possible that the fans are not engaging as it thinks the car is cold?
is there a temp sensor that i could locate and test / replace to see if this is (atleast part of) the issue?
would maybe also make sense if the heater relay was not clicking on that the climate control is never actually telling the heater start.



so see if i have this right.
signal to turn on the heater comes from Climate control module to turn on the heater pump via RW (1) which completes the circuit to WR (2)
which triggers the relay to close completing the circuit NR (3) to YW (5) providing power to and therefore turning on the heater pump.
and the trigger from the module to trigger the realy is a negative (ground) trigger.
so to test is this is working,
if i remove the relay, turn the heater on max heat, and put a test light from RW (1) to WR (2) the light should come on. if the light does not come on that would indicate the relay is not receiving the trigger.

 

ok,
so got it working,
now that the brushes i ordered arrived i replaced those and viola it really was that simple.
so in typical fashion for me i was overthinking it and looking for problems that were not there.
I get into this habit of over troubleshooting a problem before fixing the obvious things.
I should have just ordered the brushes and waited for them to come.

Now I need to work out why it is blowing really strong from the windscreen vents but not so strong from the dash vents.
will run the climate control test tommorrow and see..

 

I need o-rings!

so after repairing my heater pump i have noticed it is leaking where the impeller part screws on.
I took it apart, tried to seal it with some gasket sealant, but it is still leaking. I need new o-rings but i need to know what size to buy.
can anyone help.
if i am not mistaken there isa slightly smaller one on the motor side and a slightly larger one on the impeller side.