HELP! I know you all love working nuisance electrical issues.... Here's one:)

[jocko]

My taillight fuse keeps burning out. Dome, License, Stop and Tail Lamps all on the same fuse (per the service manual) - and they are all going out together.

Here's a potentially helpful clue (or a useless distractor) - my gauge cluster lights are going out at the same time - and are restored with a new fuse (the same one that I replace for the tail lamps...)! THAT doesn't seem quite right.

So, NO changes to the electrical system. And this problem just cropped up. I'm cornfused as all get out. Problem is - I never notice this until I drive at night and notice the dash lights are out. @#$%^&*

I have changed the fuse and it was good to go for many days - then, all of a sudden, got caught with my pants down again. Local Barney Fife is ALL about giving out tickets for breathing the wrong way, so gotta be careful. Lucky so far.

Any ideas? I'm starting to think that somehow my tail/instrument circuits are piggy-backed and the instrument lights AND all the other stuff mentioned above are running through the single fuse - and they should not be. Still gotta get under the dash and do some more investigating, but previous under-dash time showed a what appeared to be a stock wiring system...

Would suck if this was my daily driver. Sometimes it is, but normally I have an option, so that's good.

Appreciate any ideas. Bottom line, unpredictable, unrepeatable (on purpose) tail lamp common fuse burning out. Considering just putting in a 20A fuse, but worried I'd then risk a wiring fire. And that would suck even more.
Thoughts?

[brawley]

I wonder if there is a bare wire touching somewhere or pinched in something??

[pdxhall]

You might check the light switch since that is one thing in common with the lights and the instrument cluster light.

[jocko]

pdx - that is an EXCELLENT suggestion! Thank you.

brawley, same goes for you, I will look for one of those. As much as I'd like to think the harness is all stock, 50 years of different folks driving it - who knows...

[Rich 5150 69]

Jocko, my `69 camaro had a simular problem, left tail only though, after three years of fighting it, an old timer at the time, told me to wrap a piece of foil around the fuse and let it go until it smokes, you find it, I did and it turned out the harness under the dash dropped down into the parking brake sprag...10 minutes later it was fixed...just a thought if it turns out its not the headlight switch.

[jocko]

More good gouge, thanks Rich!

[tincan1966]

the tail lights and stop(brake) lights are 2 seperate circuits. I would check your tail light harness-and am thinking you've got 2 wires shorting together in the rear. Sometimes, poor tail light grounding can short fuses also. For example, if the tail light is not grounded well, the circuit will follow path of least resistance-ie the tail light circuit and backfeed. The Stop lamps being a 20A circuit and the taillamps being a 10A it wil blow fuses. The dash lights should be connected at the fuse box. The is a terminal marker "cluster or instrument lighting" or "panel" This circuit is only "hot" with the lights on. The stop,dome,horn circuit is hot all the time.
I would check the rear lighting harness and the headlamp switch for the source of your problem. Hope it helps.

[1963c-10]

Originally Posted by pdxhall

You might check the light switch since that is one thing in common with the lights and the instrument cluster light.

Lota stuff runs through the light switch

[powerdriver 1958]

Pretty common spot to look at is the wiring just ahead of the rear bumper . I have seen some trailer plugs hacked in that were pretty bad . Years of rain water splashing under the truck will have an affect .

Also moving this thread to electrical .

[cdowns]

there are metal clips that hold the harness in place a few places on the frame rail and that is a good place to check for years of chaffing and bare wires shorting out to the frame

[fixit-p]

It would be helpful to know what year, make and model we are dealing with here.

[VetteVet]

Originally Posted by fixit-p

It would be helpful to know what year, make and model we are dealing with here.

It's one of my pet peeves. He's got a 66 c-10 by his profile.

[my67c20]

You driving my truck. Same problem this is what i found. For me it appears a crappy solder connection on one of the wires on the fuse box. I actually have my fuse box unbolted and hanging just where i can reach it. If i notice my light on my tack is out (wired to come on when truck is on) i simply reach down squeeze behind the fuse box on one of them big old wires and bingo all better. MOral of the story check your solder connections behind the fuse box.

[tr69c10]

check the turn signal switch in the column I had the same problem till I seen a puff of smoke coming out

[stsalvage]

You know Some people would say your crazy driving on the same brakes for 50 years 50 years of old bridal wires.I've owned 6 of the 1964--66 chevy trucks one thing is so true.the wires are dry cracked oiled under the hood and just plain wore out.

Until you have a fire that burns your truck to the ground you will never know.But i know of a few members that have lost there trucks and old hot Rods do to old wire harness.

Its like Pluming in your house the galvanized pipe there they used on your old house can't last for 50 years.Even the old wire jobs from 1959 would never meet code to day.

So why in the world would you trust 40-50 year old wire harness in a truck you love

New car's they be lucky to get 20 to 25 years before a rewire job is needed do to how hot it gets in the engine compartment.My fathers 1990 GMC truck his throttle body injector wires are cooked every wire exposed to the heat oil gas and any other crap that enters the engine bay.Man any one that wants to trust there kid in a 50 year old truck with out a Rewire job is Nuts.

Sorry to sound harsh But we all need lessons on safety.I know we all Love are old car's and trucks But don't cut corners on safety and duct tape or wire take is not a Fix