Hi Jag Experts, I’m having trouble understanding how my vents are supposed to work. The slider under the radio has no effect, and the temperature selection will move the fan from the defrost to center vents, but the side vents never blow any air. I know the servo is working, but outside of that, I’m clueless.
Any help would be greatly appreciated!
Thank you,
Adam
“If it seems to do nothing, it’s working perfectly.”
@Kirbert - thanks for the quick response.
What about the far left and far right vents? Is there a way to get them working? Lastly, what triggers the heater switch on the firewall. It would be nice if there is a way to have the heater vacuum switch/AC to work independently of the vents.
Has anyone “hacked” the system to create more flexibility from and airflow cold/hot perspective?
Are the SIDE (sorry, wrote center) vents open? They’re manual.
The center vent opens on cooling. A small defrost percentage is intentional, if it always blows out the defrost vents you have no vacuum but I think your system is generally alright. The slider under the radio shouldn’t do anything, but if that was intended… the idea was to have the air to the head cooler al the time or vice versa. We want hot feet in winter and a cool head in summer, but the slider is worthless in my opinion.
There are a few hacks on the old site.
http://www.jag-lovers.org/books/xj-s/27-Airconmods.html
Hi David, the center vents always work. It’s the far left and far right that never seems to blow air.
We used to call that a Gardner mod, I think, named after the guy who came up with it.
As David mentioned, center vent should be open only in cooling mode.
It’s quite bizarre that the side vents don’t blow as they are always open. You can close them only from the vent manually. So either the vents are closed or the PO disabled them??
Kirbert’s book has an extensive chapter in the HEVAC operation, adjustment and the modifications you asked.
Once you know the basic principles it will be easy to understand what, and if, something is wrong.
As Aristides say, Adam - the side vents are manually operated. There is a thumbwheel under each vent - have you turned them…?
The side vents have constant air flow at system temps, as are the other vents - but the latter opening/closing is regulated automatically. The center vents are fully open in ‘full cold’ - then reset as the set cabin temp is reached; to provide blended air to maintain set temp…
And, as David says; the slider under the radio is just a bias wheel - altering temp difference between centre vent and footwell vents. It does work, but the effect is not huge…
Frank
xj6 85 Sov Europe 9UK/NZ)
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Thanks, everyone, I’ll see if the side vents are manually disabled. Then I’ll hunt for a way to disable the always-on AC using the Gardner mod. I appreciate all of the help.
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The point of the AC always ‘on’ is that it acts as dehumidifier, Adam - eliminating window fogging.
In damp condition it’s necessary - but an option is fair enough…
Frank
xj6 85 Sov Europe (UK/NZ)
**
