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Dead Circuit ARRGH!

65_BRG_Sprite

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For some reason I suddenly have no power at #4 in the fuse block. This powers ignition, fuel gauge, wiper, wipers, and flashers. Fuse is good. Lights work. This has to be something major and I would think easily found but not to be. I'm fairly proficient at most things but not so so much trouble shooting circuits. Any ideas would be appreciated. Driving me bat crap.
 

Jim_Gruber

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Clean off the green.
 

number6

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Had same problem on the Spitfire, looked first at the emergency flasher as much runs thru that harness. Solved the problem by taking the dremel tool and wire brushing the fuse box clips. They did not look corroded but I suspect getting all the crud and oxide off them was the issue.
 
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Check continuity through the fuse block, sometimes the rivets get loose and allow corrosion. New fuse blocks are inexpensive.
 

JPSmit

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and, the obvious sometimes the fuses can burn out inside the cap where you can't see it
 

SaxMan

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Use a good contact cleaner -- There's one called Deoxit which is the "go to" for musicians and sound techs. Works well on old British Car wiring, too, like those troublesome Lucas inline connectors.

Next suggestion would be to see if there is any exposed insulation on the wires coming off the block. Wouldn't take much metal to copper contact to cause a short.
 

77MidgetMkIV

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and, the obvious sometimes the fuses can burn out inside the cap where you can't see it

This got me once- fuse looked good, but the filament was not connected internally to the fuse end cap. Also, clean the whole block shiny-style.
 
OP
6

65_BRG_Sprite

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OK- got back into it; as advised I pulled fuse box and cleaned. Examined fuses more carefully and under better light (I am a senior.) Hard to see but yes- fuse blown. Dang it- am I red-faced and tail between my legs. I should, and do, know better. Front bulbs are a tad dim so I went to Advance looking for 1034 replacement bulbs. They didn't have that particular number but their computer showed a Sylvania 7528 as compatible and the package verified that. Car does not like them at all. Pulled them and put aside, reinstalled veteran bulbs. Not totally out of the woods yet but getting closer. Thanks all! Going to piddle on it some more today, then I have really fun one for you later this evening. :encouragement:
 

JPSmit

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OK- got back into it; as advised I pulled fuse box and cleaned. Examined fuses more carefully and under better light (I am a senior.) Hard to see but yes- fuse blown. Dang it- am I red-faced and tail between my legs. I should, and do, know better. Front bulbs are a tad dim so I went to Advance looking for 1034 replacement bulbs. They didn't have that particular number but their computer showed a Sylvania 7528 as compatible and the package verified that. Car does not like them at all. Pulled them and put aside, reinstalled veteran bulbs. Not totally out of the woods yet but getting closer. Thanks all! Going to piddle on it some more today, then I have really fun one for you later this evening. :encouragement:

WooHoo - BTDT - it amazes me how easily we skip over the easy stuff. All's well that ends well.
 
D

Deleted member 8987

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I haven't bothered looking at a fuse to see if it's blown in decades. Eyesight will play tricks on you, and sometimes sustained heat causes them to unsolder from inside one cap (especially if corroded or loose connection at that end).
Buy a test light.
12V, ground clip, power on, just touch one end, then the other of each fuse. If it ain't passing power, you'll see it.
You can touch the connectors, see if there are tightness/corrosion issues there.
Put that test light in your on-board toolbox, or glove box, or under the seat...somewhere where you will HAVE it on the road...along with your box of spare fuses.
 
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