No rear heat

[JMK]

Just took delivery of new unit yesterday, 92 Chamonix. Everything in good nick, but noticed that the rear heaters vents seem to blow only cool air. Note: Rear temp slider control is set to the top of the red zone, the rear fan is turned on, and the 'cool' swith is off.

The front of the vehicle blows the appropriate warm air. Is there a separate thermostat for the rear zone that could be faulty?

Also, I notice 2 types of vent near the floor, is one vent an air return vent?

[Adam]

Mine blows hot in the rear, but only from the bottom vents. Not sure if this is by design or not, but it makes sense. It heats up the rear fast.

[JMK]

Thanks Adam,

Hmmmm...

In my case the cool air coming from the top vents does not feel comfortable in winter when its -20, so I can't see why that would be by design. But now that you mention it, it do seem to recall that the one style of bottom vent felt like warmish air, and the other style felt cool.

I wonder if we may both have the same problem.

[Adam]

I think there's a selector switch on the rear air console to have the air only come out the bottom vents. That's where we leave it set to in the winter. I think the design is to pump the warm air out of the bottom vents as hot air rises, pumping hot air out of the top vents would just create a layer of warm air near the roof.

[BCDelica]

Would seem every body has that in common, the roof vents for rear heat don't blow warm air - which you need in -20 right!

Congratulations on the new Delica!

Kev

[sahdot]

There was an old post on this subject where one of the members took the system apart and found it is plumbed that way (hot from bottom - cold from top).

I ran mine with the rear heat in max red zone, fan on hi, and the diverter lever just cheating to the bottom outlets to balance with a little more heat than cool (not in the factory detent position). The reason I left the top vents on was to point them at the windows to de-fog them. In really damp weather (rare here on the wet coast), I put the a/c on also (front and rear) - front heat selector in the red zone also - rear a/c lever just barely on min. to blow dried air around. Also the front intake air was set to recirculate-why bring in more moist air?

Interesting observation on mine was that with a/c on max front and rear - temp in the blue zone and rear diverter to the bottom vents - bottom would still blow warm.

Worked for me, but my outside temps were from -2C to + 15C, not as cold as yours; but you probably don't need the de-fog option.

Pretty sure the large bottom vent in the back is the return air.

-jim

[JMK]

Interesting, thanks for diminishing my paranoia that I had a big job ahead of me. Now time to go out and convert the headlights, as it is a balmy -9 right now, opportune time to get it done before it gets cold outside.

[Erebus]

Yup, the upper vents will only blow cold, the lower only hot. So basically, you should move the up/down slider in unison with the temp hot/cold slider. I'm guessing that the theory is that hot air rises and cold air sinks.

I generally have mine set, then turn the system on/off with the driver's dash switch. In summer, I have it set for AC, cold temp, vent to up, max cool, fan on 2. In winter, I set for max heat, vent down, fan on 2.