In a message dated 97-11-10 10:15:03 EST, you write:
> A small problem with my '73 MGB. Someone before me has installed a
> not-exactly-new Pioneer (one of those SuperTunerIIIs with the cassette)
> and a couple of 100W 6x9s 3-ways behind the seat (luckily, they were smart
> enough to buy the self-contained version (maybe made for trucks?) of those
> speakers and so didn't have to cut anything to install them, they just sat
> them in the back.)
>
> Well, the relatively-simple setup sounds great, but my hypothesis is that
> maybe it was wired incorrectly when installed or that it is simply too
> much load for the current wiring setup. I'll explain: it seems
> that the circuit for 'constant-power' is either shorted out or way
> overloaded. All the things that should run regardless of ignition
> position don't work, such as: the highbeam flasher (high-lo still works,
> just the flasher doesn't), the dashboard "courtesy light" (over the
> radio), the seatbelt/door buzzer (probably a blessing), the horns, the
> cigarette lighter, and the radio's own internal 'contant power' circuit
> also seems to be either unhooked or not in this circuit as it looses its
> memory presets every time the car is switched off long enough to empty its
> capacitors.
>
> I tracked the problem to a blown fuse in the box under the hood. I
> replaced the fuse with a new one...it promptly blew out. I switched off
> the ignition and removed the key and repeated both steps (add new fuse,
> watch as fuse frys instantly.) Both fuses were 20A...I was afraid of
> sticking larger in there for fear of damaging wiring.
>
> My question, I guess, is if anyone has any insights on this. Should I go
> with a much larger fuse? (30A? bigger still?) Does this sound like a
> problem that the addition of a mere radio would cause? Suggestions?
>
Neil:
The radio itself would draw no more that 2 amp at sane volume levels or
6 amps at insane levels. I am not familiar with this particular model, but
most designs today draw power from the battery line (constant-power
circuit) rather than the ignition line.
Bob Donahue (Still stuck in the '50s)
EMAIL - BOBMGT@AOL.COM
52 MGTD - under DIY restoration NEMGTR #11470
71 MGB - finally home after 2 years in shop, AMGBA #96-12029
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