Greetings I am working now on the non working heat/ac on a 1990 XJ6 Soveriegn. When I turn the selector to on nothing at all happens. I do hear a click sound in the control panel and was told that if I hear that click that means I can eliminate that as a problem. I have checked now all fuses, the relays under the hood and just now have the blower motor out and have checked the two relays in the squirrel cage. I tested them by simply pulling them and plugging them into another spot, the horn and all have worked fine. I also direct wired the motor to 12 volt and it works fine. With the ignition on, and the selector set to on, there is no power to the relays in the cage and no power coming from the wires that connect to the fan. I also checked at the fuse to ensure there is 12 volts and there is. I am about at my witts end. Does anybody have any idea why with all relays good, fan works yet no power to the relays and fan motor?
***** This was posted by mistake under the XJs. I am now with help from them I have found it to be the micro switch. Panel has power and the drivers side fan is working not the passenger side. The wireing that goes into the fan cage, which can I check to see if power is going to the cage and relays?
Jonathan,
If your car is a 1990 XJ6, then it is newer than the Series I, II, and III XJ6s and XJ12s discussed on this list. Although your car is badged as an XJ6 it is so different than the cars discussed here that it has it’s own list on Jag-Lovers, the XJ40 list.
XJ40 was the internal Jaguar code name for this all new car first sold in the USA in 1988.
I moved the thread to XJ40 because I wouldn’t know how to help. Try to find some schematics online, and try to work your way through strarting at the fans. Test light is sufficient for now. A last option bodge would be to wire the two motors together using a relay, They’re probably supposed to work in a pair at all times.
Again thank you Grooveman! It is very informative and I have a better understanding of how it works. I see the green vacuum “pipes” and now see where to reconnect those.
Yes, the PDF file really explains the climate control system in great detail. While the system is not quite as complicated as the space shuttle it comes very … wait, it IS as complicated !
Ok so need a bit more help on my ac heat system. Made progress and here is where I am at. I have power through the wire harness to the connector to the blower motor cage. There is power to the relay, always hot. There is NO power coming out of that relay to the mini board before the blower.
It looks like you’re making a bit of progress in your troubleshooting
On this generic 12v relay you can see that if you are getting a 12v reading at pins 85 and 86 that means a low current 12v signal is being sent to the relay to close and allow high current 12v positive power to flow from pin 87 through pin 30 and on to the fan motor.
If you put one of your probes on pin 30 and the other to ground you should receive a 12v reading if the relay is in fact closed with the fan turned on.
So by checking if the problem is that the relay is not closing (no power to pins 85 and 86) … or … it’s closing but no high current power is available at pin 87 you can narrow down your search.
Hey Grooveman , who ever had worked on it before me had left one plug undone and tucked behind. Once I connected that the passenger side blower came on! It is almost all buttoned up. There is no vacuum coming out to any of the lines, there is vacuum going to the unit. I will worry about that another time. Now on the seals on the differential
