I have a master switch installed in my Model A just for protection. During the winter i installed a new blue tooth radio that is a pain in the butt to program. Every time I turn off the master, the radio looses power and along with it, it's memory. I'm considering adding a jumper across the master switch with a 2 or 3 amp fuse just so the radio doesn't loose power. I would think cars with computers might have similar issues. Has any one else done this? Good idea or bad?
it defeats the purpose of the master disconnect if it was installed to bypass a slow drain
but the remote disconnects often have this built in
you can do the fused bypass or just fuse the memory wire to the radio off the battery
if you do the fuse bypass...
buy lots of 3 amp fuses as it will blow anytime you forget to turn the disconnect on and try to start it
I ran a wire to separate sub fuse panel for those kind of 'gadgets'. If I recall, that panel has a 30 or 40 amp maxi- fuse and each of the sub circuits has a fuse size intended for whatever 'gadget it feeds.
That convoluted wire cover, LHS as you look at it leads back to the trunk, the battery, the switch and the maxi-fuse to the sub panel mounted on that narrow piece of wood for the upholstery. I also have a maxi-fuse on the main panel for added protection.
dave where is that fuse panel located i was going to put mine under dash but now im thinking maybe under /behind the bench seat where it will be easier to keep dry in my 38 chevy pu cab
Depends on why you use the disconnect in the first place. if you use it to keep the battery from draining then using a separate fuse panel or jumpering a small fuse across the disconnect will do you no good. same drain as before. BUT… if you use the disconnect for theft protection, then yes, the small fuse bypassing the disconnect keeps the gizmos happy, but if someone tries to start the car the fuse will blow and the starter won't engage. might slow them down enough to discourage a theft.
just remember that someday u'll need to get to that box to figure out something.. so where ever u put it make sure u can get to it without pulling the seat or what ever.
You might think about isolating the radio completely separate from the rest of the electrical system via a relay. Memory wire straight to the battery, existing hot wire FROM the radio to the common contact on a relay, the NC terminal would be left blank and the existing hot wire from the fuse panel, leading to the radio...... to the NO contact. The coil terminals 86 and 85 .... one to ground and one to a ign switched 12v source.
turn the key off relay opens and disconnects the radio from the electrical system except for the memory wire..... in theory there should be no parasitic drain (with the main disconnect off) from anything else except for the memory wire.
Might work.
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