Just wanted to see if anyone has heard of this happening. Car has over 200k but still runs good when the fuse isnt blown. It blew while driving 45 on an old road. It worked fine for a couple of days and another fuse blew. Several replacements have blown as soon as the car is turned on. Could this be the battery or cables? Thanks for any info or suggestions.

Battery - no. Cables - possibly. Blowing fuses can be a HORRIBLY difficult problem to diagnose, expecially - like in a case like yourse - when it's intermittent. With 200k on the car, it could cost you more than the car is worth to have someone find the problem (seriously).

Everything on that circuit after the fuse is individually fused except for the alternator and the wires that go to it and the seat heaters. The fact that it doesn't blow unless the engine is running points to the alternator.

The fact that it doesn't blow unless the engine is running
I'm not sure that's the case - he actually said Several replacements have blown as soon as the car is turned on
cartertaylor - pls clarify.