I was asked to assist in determining why the climate control fans suddenly stopped working on a Series 2 xj6. My efforts were remote to the car and via phone.
We went down the usual path of testing fans and checking for power on the fan relay pack. All checked fine and determined the issue was no power to the low amperage control side.
All fuses checked fine…but as we dug a bit further…we found no power coming into the fuse block ignition switched AC lines.
We suspected a faulty ignition switch since we were getting no power to the fuse block. As the detailed wiring diagrams in the manual came out…we found the existence to the " ignition protection relay" . apparently this relay is mounted behind the dash facia and gauges and is switched via the ignition switch and controls AC and windshield wipers.
When my friend went to do the hands on testing…he confirmed his windscreen wipers indeed did not function. Upon removal of the dash facia…he found one of the leads from the ignition protection relay had come loose.
After a clean up and reinstallation…power was returned to supply the switched circuits in the fuse block and everything began working again.
Can anyone offer any clarity of what years and models have this “ignition protection relay”? Xj6 series 2 and 3? XJS models?
I never had reason to dig this far into the AC circuit…and was surprised by this relay…I never stop learning.