<VV> Blowing fuses

[Hugo Miller]

Forgive me for butting in, but I don't think this is clear; the 
courtesy light for sure is grounded by the door switch. Possibly the 
glove box also. So anything that goes to ground on those circuits will 
just bring the light on and nothing else.
If there is a short between the fuse and the lamp itself, that will 
blow the fuse. But downstream of the lamp it won't.
I think the only thing to do is trace every circuit that is fed by that 
fuse. The light switch itself must be upstream of the fuse, in which 
case you can rule out the tail lamps and brake lights as the fuse blows 
with the lamps off and presumably without your foot on the brake.
You need to find a circuit that is live with everything switched off, 
and that to me points either to the clock, or to the wiring between the 
fuse box and the courtesy lamp or glovebox lamp. Have a peek under the 
dash to see if the wires to the glove box lamp or dome light have chafed 
through on anything.
Kenworth trucks, incidentally, have a brilliant system whereby there 
are no live feeds to the dash; every switch on the dash simply grounds a 
relay that activates the circuit. So if anything shorts out behind the 
dash, instead of the truck going up in flames, all that happens is that 
a circuit comes on when it shouldn't. Clever.


On 2020-05-03 19:36, Bryan Blackwell via VirtualVairs wrote:
> As I recall the tail and brake have the switch control the hot side,
> but the glove box and dome/courtesy are switched on the ground side 
> so
> I would focus your efforts on those.
>
> --Bryan
>
>> On May 3, 2020, at 1:12 PM, Kent Goddard via VirtualVairs 
>> <virtualvairs at corvair.org> wrote:
>>
>> The 10 amp fuse protecting the tail/brake lamps, glove box and 
>> courtesy lamps and clock (etc?) in my '66 Corsa blows upon insertion, 
>> even with lamps off.  My level of electrical expertise is low, but it 
>> sounds like a direct short to ground.  I've done a cursory inspection 
>> of exposed wiring in the engine compartment and under the dash and 
>> haven't found any damaged insulation. Any suggestions of most likely 
>> problem areas that I should investigate first??  Thanks.
>>
>> Kent G
>> St. Louis, MO
>
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