For almost 20 years I subscribed to various Jag-Lovers lists::XK, saloonx and E-type. Those lists helped me through frame-off restorations of six Jaguars (1951-1964) three of which were pictured in a magazine-"Jaguar Enthusiast." Those lists provided assistance online and offlive which helped me tremendously! Now I have used the Forum for the first time and was greatly disappointed.

I did learn what my problem was, but when I asked for someone's email and provided mine,, Graham told me that was not allowed and ended my thread. Now that I know the ruies, I'll try to continue. My apologies to Graham for not knowing the rules.

The problem is my RH blowers runs constantly. I think the access panels should be easy to remove to gain access to the blower. But how do I determine which component is causing the problem and what the part numbers are. Also , where can I get the parts?

Thank you guys for your help.

Frank Morse
1991 V12 XJS conv wirh a Mark III a/c.
so

 

Frank,
I've moved your thread from the new members section to the XJS tech section where I'm sure will get the help you need.

I believe the main reason the other thread was closed was because it was in the "New members section" which is solely for the introductions of new members and not for technical discussions, in addition you did not provide details of your vehicle.

I see you have provided the necessary details now, I'll add those to your signature so they show up in every post. (starting with your next one)

 

Thank you for your understanding. Am I subscribed to the XJS forum or do I need to do something else? thawnks again

 

Graham,
, Can I or will you correct the typo from XJE to XJS?

 

Fmorse,

I was also on jag-lovers for a long time (even back when it was an email list system), and you won't be disappointed here. Best XJS forum with the most helpful and insightful members.

As to your problem, this is a quite common. For some reason the fans are wired in such a way that are always wired 'on' and the circuit turns them 'off'. When there is a component failure the fan is always 'on' rather than not working at all. In the short run you can pull the fuse to that fan so it doesn't run your battery down. In order to fix it, the entire blower unit needs to be pulled and you'll have to solder in a replacement of the failed part. I can't remember the exact one that fails, but if you search the archives you'll easily find posts regarding this and the circuit drawn up (archive search is much better than at jag-lovers too).

Cheers

EDIT: You might find this helpful on how to remove the blower: http://www.bernardembden.com/xjs/hvacmodule/index.htm
And this on the circuit with the transistor that fails: http://www.jag-lovers.org/xj-s/book/acblower.htm

 

All done.

 

Thank you

 

More likely than not, the Darlington transistor has failed. The circuit diagram and parts list at the Jag-lovers link is all you need, depending on where you are I have found Digikey a great place for the components.

 

Thank you for providing me with the links., If the transistor is the problem, how do I know for sure if that is the problem and what does it look like? Can you help me with part numbers for the components and a source? Thanks again.

 

The way the circuit works is the circuit is powered all the time and the transistor makes ground when needed. When the transistor fails, it always provides a ground path and loses it's switching function.

Here is a suitable transistor: https://www.digikey.ca/en/products/d...J11016G/919445

 

Thanks. I just ordered it. I assume it is accessible once I remove the blower. Correct?

 

Yes, there is a small circuit board inside the blower housing, You'll have to unsolder the old transistor and solder in a new one. Be careful to protect the new transistor from soldering heat, electronics don't like being too hot.

Much of the process is described here: http://www.jag-lovers.org/xj-s/book/acblower.htm

 

OK. I am making progress, but I have hit a snag. I unbolted the blower motor mounts, but the blower will not come out. It appears to be stuck at the top. I opened the recirculation flap at the bottom (it will only open about 1 1/2 inches). I tugged on the blower motor, but am afraid I will break something. Am I missing something?

 

No, but the bottom flap MUST be open to remove the unit. It is a good idea to use a block of wood to hold it as open as possible. It will be stuck because the rubber gasket adheres very firmly to the body! You just have to use brute force to rock it about to break the seal. If the bottom flap is not wide open the top flap overlaps the body like a lid and prevents the blower moving.

 

I think my problem with removing the blower is the top flap is not closing. How much does the bottom flap have to be open for the top flap to be closed enough? I have tugged and tugged on the bottom flap, but I believe it must not be opened enough.

 

OK. Some progress. I finally got the blower out I think I was not holding the lower flap open enough.. Success!!! I found the panel with the components. It was riveted on. Now I just have to wait for the transistor I ordered. Do I need to replace the other parts? Thanks for all the help so far

 

Hi guys,
I have removed the blower and replaced the transistor. I hooked up the wiring and the problem (blower running constantly-RH) is resolved.

Now I have a problem reinstalling the blower. I have wedged the bottom flap open but cannot lift the motor high enough to engage the attaching bolts.I think if I can align the top flap with the hole in the cowel it will go higher, but cannot lift it high enough. No wires or anything else is in the way.

Suggestions?

Frank Morse

 

You have to wriggle the thing back into its oval hole. Bottom flap right open, push wriggle push etc etc.

 

Thanks. I'll keep trying.

 

Success! The A/C works fine now. Thanks for everyone's help.

Franjk Morse
Tampa, FL