No cabin heat

[ajay16]

I have no cabin heat at all, it just blows cold.

Resevoir is full.
When I switch on heat and fans just the fans blow.
Liquid in the resevoir gurgles and moves
Checked heater fuse in cabin.

A/C works just fine and is icey cold.

Reading fault codes I did have the B1108, cleared it and tried again but it hasn't come back so far...

Any clues or things I should try?

 

[MickeyS70]

I have no cabin heat at all, it just blows cold.
Resevoir is full.
When I switch on heat and fans just the fans blow.
Liquid in the resevoir doesn't move.

There are two reservoirs, one for the cooling circuit (boot), the other for the heater (bonnet).

I assume you checked the front one, if there is no water movement, the pump doesn’t seem to be running but usually that would throw a DTC?

Best to start with the basics, did you check the pump’s fuse and relay?

For details see service manual
http://mmc-manuals.ru/manuals/i-miev/online/Service_Manual/2012/index_M1.htm

 

[ajay16]

Upated my original thread as I realised the car wasn't in a 'ready' state when testing earlier. First realised there was no heat while out driving. Water in the front tank does gurgle and move.

Fuse checked for the heater by the drivers footwell.
Is the relay under the bonnet? I couldn't see a mention of that in the repair guides - thanks for the link, super helpful.

 

[MickeyS70]

Upated my original thread as I realised the car wasn't in a 'ready' state when testing earlier. First realised there was no heat while out driving. Water in the front tank does gurgle and move.

Yes, heater is powered by HV, only works in READY

Fuse checked for the heater by the drivers footwell.
Is the relay under the bonnet? I couldn't see a mention of that in the repair guides - thanks for the link, super helpful.

The 12V fuse is for the low voltage heater controls not the actually heater itself. There is a 20A HV fuse but that’s not accessible (inside HV pack). No heater relay.

Easiest way to determine if any of the 3 elements inside the heater are working is to turn on the heater when READY but stationary, the ‘consumption needle’ should move noticeably and RR will decrease accordingly.

 

[ajay16]

I've done some more digging today.

It looks like i'm getting no outdoor temp reading on OBDZero, could that be the cause?

Also looked at everything with a thermal camera.
Front tank gets up to temp, is swirling away etc pipe behind hot too.
Right hand side on the passenger footwell where all the white box heater gubbins is, is also hot.
A wire behind the glovebox also.

I gather I should be seeing more heat from behind the glovebox/in the footwell than i'm seeing as that's where the heater is?

Haven't checked the relay under the bonnet yet, job for this week.

 

[MickeyS70]

It looks like i'm getting no outdoor temp reading on OBDZero, could that be the cause?

Don’t think so, the heater control is based on water temperature

Also looked at everything with a thermal camera.
Front tank gets up to temp, is swirling away etc pipe behind hot too.

20deg C is merely warm, you should see double, if not triple that..

The heating power OBDZero displays is ‘virtual’, i.e. an assumption that the heater works as it should, not an app issue rather the way the car is designed. Check the total battery power value, it has to be higher than the heating figure, if it’s working correctly.

 

[ajay16]

Tested the relay under the bonne today, two top prongs (shown with multimeter in) get 15v whether the heater is on or off.
The other two connectors get nothing at all, heater on or off there's no voltage.
10A fuse checked under there too.
Checked both grounds, they look fine.

Checked the wiring connector B306 in the junction block in the drivers footwell as per the diag instrustions for fault code B1108 - the car does have a Cobra imobiliser and tracker fitted which was tapped in to two of these wires, but everything else looked ok.

Then I turned the heating on to get the readings for the voltage difference on OBDZero, and leaving the car for 10ish minutes heat did start to come through!
I'd say it was more than warm, but not hot. Vents said air temp coming out was between 45-48 degrees?

Is it normal for it to take that long for it to warm up?
I think this is progress as the other day I left it the same amount of time and the air was near enough cold.

Pipe temp at the back of the reservoir still only got to 34-36.
Pipes under the car were also warming up when I checked.
Outdoor temp was 3-4 deg.

 

[MickeyS70]

I took a screenshot of my OBDZero values today, you can clearly see that the overall battery power is higher than the assumed heater output.

If that’s not the case, the heat output is insufficient and the PTC heater needs replacing.

 

[ajay16]

Ok so mine could be dying then? Or some of the heater elements aren't working?

What's the best option to replace it, a used one from a breaker I gather?

 

[MickeyS70]

Ok so mine could be dying then? Or some of the heater elements aren't working?

What's the best option to replace it, a used one from a breaker I gather?

A heater consist of 3 different resistors that produce approx 1/2/3 kW of heat output. They are activated individually or in combination via three control lines. Problems with low heat output are rarely caused by a faulty control circuit.

There is no reliable way to bench test the heater without a HV supply, as it’s believed to be made by combining NTC/PTC elements.

Getting a replacement from a breaker’s yard may therefore be a bit of a gamble, but then beggars can’t be choosers..

Btw someone mentioned Ford Transit Connect Electric use compatible heaters

 

[ajay16]

Hmm at nearly £600 that sounds like it may be a big gamble.

Just had a look at Outlander PHEV PTC heaters. They look very very similar, and can be had for £150.

 

[MickeyS70]

Just had a look at Outlander PHEV PTC heaters. They look very very similar, and can be had for £150.

IIRC PHEV’s primarily use a conventional heating system, but have a (supplementary) electric heater when driving in pure EV mode? Therefore I’m (purely) guessing it has a lower heat output compared to the i-Miev but that may still be a (somewhat) improvement on your current situation.

Nothing ventured, nothing gained.

@jray3 might be able to help you out with pre-loved OEM heaters

https://myimiev.com/threads/i-miev-cabin-heater-stop-heating.5338/page-2

 

[jray3]

Thx Mickey, I do indeed have used heaters in stock, and will include the hoses, assuming I can get them off cleanly. I’ve also used our heater as replacement on the Azure Dynamics/ Ford Transit Connect Electric of 2010