Hello everyone

I just have to say thank you to everyone. Your help has been much appreciated. Here's another little issue ( I hope it is )
My ac system. I have the delenair 3 system. My recirculation knob when pulled out does not engage the flaps at all. It seems as if the button is dead. It does however working when I change the temperature settings. Everything else seems to work ok. Defroster works correctly heater works fine, AC works good but not cold enough. My guess is that the recirculation flaps are not closing causing fresh air to enter the cabin. If I wedge a screwdriver into both bottom flaps the air cools perfectly. So the big question is How do I get that button working aside from keeping the screwdriver in there. Is there a fuse for just the recirculation flaps? This is driving me crazy.

Thank you.

Evan
89 Xjs convertible

 

to clarify a bit....

There is no *driver controlled* recirculation function or knob.

Pulling the temp control knob outward will provide manual control of temperature but does not specifically or exclusively control the recirculation flaps. Of course, if you dial-in the max cold setting the recirculation flaps should close.

So, I guess your recirc flaps are NOT closing under any circumstances, yes?

Cheers
DD

 

Correct. No movement from the flaps at all opening or closing. To get my car cold I have to go under the dash and wedge the doors open for recirculation. If not I get fresh air mixing in.

 

Don't leave me now :-)

 

I'm away from my Delanair manuals at the moment. If nobody chimes in before tonight I'll see what I can dig up for you when I get home

Cheers
DD

 

Thank you so much

 

Anyone?? Please

 

The recirc flaps are held closed by vacuum and open without vacuum.
So, it sounds like there is no application of vacuum to close your recirc flaps.

On/off vacuum supply comes from a solenoid on the left side of the climate control case, down low. Look for the *blue* vacuum line. The solenoid is electrically controlled by the climate control ECU. It will have a red/blue wire and a green wire.

I guess the easiest place to start to be checking if the solenoid is connected and and the vacuum hose attached.

You could pull the blue vacuum hose and apply vacuum with a hand pump to see if the recirc flaps close.

Assuming they do, I reckon....

A) The solenoid is not being commanded by the ECU or
B) The solenoid is faulty or
C) There is no vacuum supply to the solenoid

Near as I can tell, when max cold is asked for the ECU should provide 12v to the solenoid on the red/blue wire (most of the system components work on 5v, by the way). The solenoid then allows vacuum to the recirc door actuators, closing them.

Hope this is enough to be helpful and/or get you headed in the right direction.

Cheers
DD

 

Thanks Doug. I'm gonna give it whirl this weekend. I'll let you know what happens.

 

No luck. Any chance of emailing me the operations manual for the delanair III?

 

I don't have in an e-format. But here's a couple of many sources

Jaguar #42 Delanair Mk 3 Air conditioning unit manual, Language: English, Category: Owners manuals

Collection Car

Cheers
DD

 

Is there a relay inside the blower housing that could've failed or is it just run on vacuum? Everything checked out fine. The solenoid is providing vacuum to the blue line. I even unplugged both lines going to the blower house diaphragm and there is vacuum going to them. Could it be a faulty vacuum diaphragm? Would it effect both housings? Another problem is that when I have a/c on full cool the is no vacuum going to the heater valve. Can't seem to find where that small black hose connects to comming from the heater valve. I follow it thru the firewall both cant seem to find it on the other side. Does is change colors inside the cabin. I'm suspecting the line may be disconnected.

 

The vacuum source is on the end of the A bank inlet manifold. This goes to a vacuum reservoir which is beneath a bolted-on rectangular panel on the passenger side of the engine bay, nearly horizontal, by the firewall. This panel is EXACTLY in the equivalent spot on the passenger side where the pedal box/brake pedal is bolted in on the driver's side. In fact on RHD cars, this panel and the pedals are in the reverse positions.

If you look at the panel (which might involve you removing the windscreen washer reservoir first, depending on your model) you will see that TWO vac lines go through it. One comes from the vac source on the inlet, and another comes out from the heater unit and back to the heater valve. One of the lines, I think the vac source one, has a non-return valve in the line, which may well be jammed, and causing problems.

Worth checking the vac reservoir is holding vac, they very rarely go wrong, in fact nobody knows they are there!

Greg

 

There is either in jag-lovers (an old thread) or possibly in "the BOOK" ) a fix for this where in effect you wire in an extra relay and find a suitable place for an extra switch to control the flaps at will. If you cannot find it it will consist of a relay which when de-energised allows the original system control the vacuum solenoid for the flaps, but when activated cuts the connection to the system and applies 12V directly to the vacuum solenoid for the flaps. Just do make sure you do not feed 12V to the system ECU instead