Acquaintance of mine has a 93 XJS 4.0L and both fans quit working. I don't
think both fans would fail at the same time. All fuzes are good. Any suggestions?

Submitted by dougdwyer1@com… on Tue, 03/22/2011 - 23:33

I've fixed a couple of these systems by cleaning all the connections and grounds. If your XJS is like many others you'll find evidence of moisture behind the dash.

Look for the tiny-ish plastic connectors with tiny-ish wires and even more tiny-er contact pins which might well be loaded with corrosion. A couple are rather high up on the left. Four or five others are within easy reach.

On either side of the climate control casing is a vertical, sheet metal dashboard brace. Look for ground points on the braces.

Cheers
DD

Submitted by dstone@gi.alaska.edu on Mon, 03/21/2011 - 15:29

You may have the same problem I am having with my 1987 XJSC Cabriolet.
The climate control was working fine, then the next time nothing happened when the switches were operated. No fan, no heat, no sound. Somebody must have torqued the temperature control switch because when I took it apart to investigate, the whole potentiometer had been through 360 and was totally trashed with wires pulled off.
I replaced it with a new switch, but still nothing. I checked all the power wires and fuses and eventually decide it had to be the electronic control, the piano box, part CAC3082. On checking the voltages on all the pins, very few matched those listed in the shop manual. I bought a used replacement, but it too displayed all the wrong voltages.
Does anyone know if some Jaguar enthusiast has unraveled the code for the piano box? I have access to computer wizards, but they canÔÇÖt do much without the code.
I understand that new ones are available for $2000 or so, but this is a big fraction of the value of my car!
The alternative is to bypass the box and switch things manually? Any suggestions as to how this can be done? It would be nice to have the de-mister, and perhaps some heat!