XJ6 1978 ser.2
no way to control the cold blowing air, is it the amplifier or the converter?
No way it blows warm air,
WalterI would first suspect the amplifier.
You can easily check that the servo works with a 9v or 12v battery, details in the archives and in Kirbyâs book.
Other possibilities could be the potentiometer at the servo unit and the ambient temperature sensor (thermistor).
You likely have early AC version, Walter without the amplifier?
In the early version the heater valve was opened by vacuum, so check if the heater valve operates, and has vacuum?
Frank
xj6 85 Sov Europe (UK/NZ)
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Hi Walter,
try to check the 1A fuse of the amplifier. If it is blown, there will be no servo control. Fuse is located behind the small LH cheek panel attached to the transmission tunnel.!
André!
Thanks, Iâll check the fuses.
Walter
Iâll check it, thanks.
Walter
I checked my vacuum hose yesterday for the hot water line valve, the hose might have been a
little loose.
Started the car up to check the vacuum line to the valve , it pulled the valve open.
After that the warm air was blowing into the car from the heater and everything seems to be OK.
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ââŠseems OKâ is likely as good as it gets, WalterâŠ
Frank
xj6 85 Sov Europe (UK/NZ)
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Andre!
It happened again, the cold air was coming in instead the heat.
Could it be a bad thermostat on the right side?
Walter
Now we really do need to know what AC set-up you have, Walter - âDel 1/aftermarketâ and Del2 needs entirely different approachesâŠ
Frank
xj6 85 Sov Europe (UK/NZ)
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Hello Walter,
Please check the two hoses to the heating radiator. Are both getting warm? If not, the water valve is defective and should be replaced. The water valve opens with NO vacuum.
What happens when you change the temperature? Do you hear the servo control unit (it sounds like a little electric motor)?
André
Itâs pretty safe to say that Walter has the Delanair Mk II.
All Series II cars to the USA had climate control. And all Series II cars with climate control used the Delanair Mk II system.
There were of course the âheater onlyâ cars, which couldnât have been but a tiny percentage of production⊠and USA market cars were not configured that way.
Cheers
DD
In which case the AC am-p would be the prime suspect, Doug?
In which case; the AC being in âcoolingâ mode should open the center ventsâŠas a crude indication?
Frank
xj6 85 Sov Europe (UK/NZ)
**
Thank you Frank
Iâll make some more tests this weekend to check what happens as it
warms up. Make some notes.
Walter
As usual, yesâŠafter all the easier (and less expensive!) possibilities have been eliminated.
Yes, and when in heating mode, most of the output going to the lower vents. Together these responses suggest the system at least understands temperature change requests and is trying to complyâŠeven if 100% success is not achieved.
Square one, though, is turning the temp knob and listening for the whirring of the servo. A no-whir situation must be fixed first.
Cheers
DD
Took the car out for a good drive to test the air cond, well started up well,
I did not turn the system on, waited till it warmed up, it put out heat.
It turned out heat, then I turned the system on, to LOW.
Temp was set between 85 and 65.
After a few minutes it had some cooler air come in to mix with the heat,
and everything seemed to be OK .
Walter
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The âLowâ and âHiâ setting only controls the fan speed, Walter - the AC amp still controls the cooling/ heatingâŠ
In âAutoâ the system also controls fan speed; the fans will run at high speed until the set cabin temp is reached. It then drops fan speeds to low to maintain cabin temp - using fan speeds a prime control of cabin temp. A sign of a well functioning system is fan speed variationsâŠ
As an aside; when the cabin temp is below set temp - system goes to heating. If above; system goes to cooling - ie, if the cabin temp is below set â65â; the system will go full heat. And if above â85â - the system will go full coldâŠ
Frank
xj6 85 Sov Europe (UK/NZ)
**
Thank you very much for all that information.
Walter