Had no issues until today when the aircon started blowing hot then cold then hot again as well as the battery light coming on and going off again after a few seconds.
I stopped at the local KMart Tyre and Auto store and had the battery load tested. Battery passed. They did some measurements of charging voltage with air con off then on and said "the alternator is on the way out". Anyone else had these symptoms with the alternator ending up the culprit? The thing that gets me is it came on all of a sudden - I had no issues with the battery light coming on until today. It was really hot today - could that be a contributing factor?

 

Clackavosticus, while I am not saying that it won't be the alternator, very few alternators have failed in X-Types. So, that is a blessing and a curse.

This is what I want you to try: With the car cold (having set for the night for example), start the car and turn on a lot of electrical loads (seat heaters, A/C on high, headlights on, and rear defroster). Go for say a 5 minute drive (need the engine RPMs up because of the load we have on the alternator). After the 5 or so minutes, pull off somewhere and open the hood/bonnet, remove the cover off of the battery box and cup your hand OVER!!!!! (DO NOT!!!!!!! touch) the battery terminals. Do they feel about the temp of other components under the hood or are they very hot (may be one or both terminals). If you think that you could fry an egg on one of the terminals, then your problem is a bad cable on that post. That is what I would say are 99% of the problems that are electrical system related on the X-Type.

If this is not the case, then let me know and we can take things from there.

 

Looks like you were right. I took it for a drive with accessories on and when I parked it I tested the cables for heat. Standing facing the front the left side cable post (I Think that's positive? - correct me if I'm wrong) was considerably hotter than the other cable. I especially noticed the heat when I put my finger on the metal tab coming off the cable connector. Yes you told me to cup my hands but it wasn't hot enough. It was hot enough to give me a burning sensation when I put my finger on it but it wasn't radiating that much heat. The cable must be in the early stages of deterioration. Looks like the diagnosis is a corroded cable. Its too close to Christmas to get the work done now. Will do it in Feb when I come back from Holidays (I'll ride the motorcycle in the meantime). Thanks for your help Thermo. Looks like I'll save a bunch of money - an alternator change out would have killed me...

 

Clack, try it again and turn every electrical thing you can on for the drive (blower, radio, seat heaters, rear defroster, all headlights including high beams) as Thermo said, that load will help heat up the cable if it's failing. I prefer going for about 15 minutes, mine intermittently does this when I've spent hours goofing around with the lighting on my car. Battery light comes on, cable is cooking hot.

Leave it for a day and it doesn't occur again until I overload the wiring messing with my lights. I'm sure my cable is failing but, I cheated a bit last time and while cooking hot, sprayed some Fluid Film into the top sheathing of the cable. My thought process was the baking hot cable would help the Fluid Film migrate down inside the cable. It seems to have bought me some more time, as I have not had a reoccurance for months.

Being raised on a ranch and farm, we think Fluid Film rates right up there with bailing wire, pliers (& later duct tape) for being able to repair dang near anything, lol!

 

Probably don't need to do further testing as when I initially tested it the positive cable was considerably hotter than the negative cable. I am satisfied with the diagnosis that the cable needs replacing. I have booked in with my auto electrician to make up a replacement in early Feb 2020.

 

99.9% is the cable ...just cahnge it

 

Correction to my last post - I am no longer going to get the autoelectrician to make one up - I am going to buy an already made up sample from ebay sold by Jagdaim, an aftermarket supplier of parts for Jags in Australia. Hopefully this way it'll be in spec.

 

Clack: I've talked to Thermo on several occasions about my engine light coming back on AFTER I had my alternator changed. He does give sound advice and I've tried his ideas. I do however, want to caution you to keep an eye on your batt light coming back on again after changing out the cable.
My batt light was acting just like yours and when I finally brought it in. Sure enough, my alternator was dead as a door nail. On top of that, it fried my battery so it cost me for a new battery which is about wayyy too much for a battery to cost, plus all the associated alternator expenses.
If the batt light comes back on after changing out the cable, I'd suggest you hi-tail it in and get the alternator changed out so you don't get hit with a battery cost also.
By the by Thermo, my batt light has not come back on after my mech fixed that corroded ground I mentioned.
Boston

 

Don't worry - I won't ignore the warning light if it comes on after changing out the cable...