The heater in our old 1987 XJ6 has has a mind of its own for about 10 years now; heating when it wants to, blowing outside air other times -- even in the dead of winter.

I know some of the cars have this problem but I wonder if there is a reliable fix for this? Bypassing a controller with a toggle switch comes to mind.

Are there any references anywhere that deal with solving this issue? I imagine even the cars with retrofitted drivelines have similar issues to solve on the interior.

Thanks,

RGW

 

These changes are accompanied by the usual whirring sound, yes ? If so, most likely it's the amplifier acting up.

There are some tests for some of the individual components so if you have a multi-meter and want to give it a whirl, just shout. There's no DIY test for the amplifier electronics and testing the rest of the system requires known-good amplifier. Of course, any testing is meaningful only if you can do so while the system is acting up.

It pretty much comes down to replacing the amp and going from there is it doesn't work.

Cheers
DD

 

Yes, there's always that sound and flaps moving etc.

I'm somewhat handy with the electronics. What is inside the amplifier? Integrated circuits or perhaps just analog discrete components? If it's the later maybe it can be repaired if a schematic is available.

Also, are there any diagrams posted on how the system works and all the components involved?

Thanks

 

I've never seen a schematic for the amplifier internals but there's probably one out there somewhere.

Cheers
DD

 

Here's a schematic of the system, plates 25.1 and 25.2 specifically. Don't scroll too far you'll find yourself unexpectedly in the XJS guide instead of the XJ6 !

http://www.captainjaguarscathouse.co...ec%20Guide.pdf

Cheers
DD