You also might want to go ahead and pull the blower then give it a spin and see if the bearings are getting hard to turn. This can cause the motor to pull more amps than it's supposed to. Normally this would blow the fuse, but if someone put in a bigger one, I could see the fault you have happening.

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Whoever said there's nothing more expensive than a cheap Mercedes never had a cheap Jaguar.

83 300D Turbo with manual conversion, early W126 vented front rotors and H4 headlights 401,xxx miles
08 Suzuki GSX-R600 M4 Slip-on 26,xxx miles
88 Jaguar XJS V12 94,xxx miles. Work in progress.
99 Mazda Miata 183,xxx miles.