Questions on 1980 fuse panel and wiring

I read something about circuit breaker in the upper right and lower right parts of the fuse block? whats the giant thing? a flasher? maybe the CB i thought of, i imagined smaller

i have a fuse in every spot that has 2 prongs. some circuits have just one, even non-tapped ones(just a few) .


as far as orange taps go... 1 factory is necessary to my understanding, other 2 feed options? 1 of my options is roof lamps i think i see following the orange and white wire, i think.

the pink.black wire feeds.... switcher for gas tanks???(clear plastic tap)

whats this module relay thing?


this looks OK, headlamp switch missing a wire, perhaps needed for more interior lights or something like extended cab idfk, underhood light maybe? im okay with what i see on that

Missing wires, i assume for auto trans and cruise stuff

is the ground bus supposed to have more> also surprised mine is clean Lol

otherwise.. extra wiring was un-nicely routed stuff left by my Gpa otherwise i been trying to clean up that old wiring by 1)removing it 2) redoing it if I need to. The only one of mine visible is the purple wire with black tessa tape. it is a fuse tap that feeds my eletric choke key on from wiper circuit add a circuit

also trailer brake controller that had a lot of splices and wires... mostly in the way of course. so those are obvious.
buzzer never worked nor do i know what it buzzes for, same with seabelts. i could eliminate those if they are wasting space or in the way.


also going out on a very large limb and assuming this flasher was wired in... for trailer lights???

lastly, how do the taps all work? they provide power based on what key is positioned on? like acc power you could tap for something to only turn on in acc? And the fuse next to it would fuse that circuit? i guess i dont know how they work too much

This all still fresh in my mind, I built a new dash harness for both my GMC and Olds this past winter

The white wire is brake light input from the brake switch
Green is right rear turn (also the brake light)
Yellow is left rear turn (also the left brake light)
Purple is power from the hazard flasher
Brown is power from the turn signal flasher
Light blue is left front turn
Dark blue is right front turn
Black is the ground trigger from the horn button to the horn relay

later column will also have a light green and tan wires, those go to the key in the ignition switch inside the steering column.

The extra unused cavities in the turn signal connector are for car that have a 3rd brake light, cornering lamps, or other exterior lamps.

This is almost certainly your horn relay. If so, it will have a dark gre en, orange, and black wire. Orange is power from the horn fuse, green goes to the horn, and the black wire is the ground trigger to the horn switch in the column

The ground bus connector probably will have more spaces than wires. If your truck has options like power door locks/windows, cruise control, etc that’s where they would be grounded

This is either your hazard or turn signal flasher. If it has a orange/brown wire, it’s hazard. Purple/blue, it’s turn signal. On my 81 GMC, both flashers were in the fuse box (I think)

This is your seal belt warning buzzer.

This is almost certainly the circuit breaker that would supply power to the buss bar behind the fuse box for things that are powered at all times. The buss bar supplies power to individual fuses for taillights, brake lights, dome lamps, etc.

I’m guessing the circuit breaker your asking about is in the spot labeled power accessories? This diagram shows the buss bar feeding the various fuses

Matt69olds said:

This is either your hazard or turn signal flasher. If it has a orange/brown wire, it’s hazard. Purple/blue, it’s turn signal. On my 81 GMC, both flashers were in the fuse box (I think)

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this one is in the engine bay and i have one for fuse box, i had removed it from the fuse box to take the pics. so i had... 3 in total?

The flasher is under the hood? That seems....peculiar. I can’t think of any reason why someone would put it there.

Matt69olds said:

The flasher is under the hood? That seems....peculiar. I can’t think of any reason why someone would put it there.

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but in addition to the one in the fuse box. im guessing it was maybe auxillary for trailer brakes.. maybe something wired to switch... i cant think of why

AuroraGirl said:

but in addition to the one in the fuse box. im guessing it was maybe auxillary for trailer brakes.. maybe something wired to switch... i cant think of why

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Maybe some kind of Aux flashing lights for plowing? This was on your Grandpas plow truck, right? My 80 does not have a flasher in the engine bay.

Bextreme04 said:

Maybe some kind of Aux flashing lights for plowing? This was on your Grandpas plow truck, right? My 80 does not have a flasher in the engine bay.

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its definitely not stock BUT that is a very good idea, I think its the case. here ill show ya

see on the left side, the amber ear on headache rack? that has a 1156 just like the front and rears, and were hooked up to ****** wiring that ran off turns and hazzards. THats a 1/3 increase of load just in everyday use. Esp without LED. Well, technically less but 194 are negligible comparatively.
The front also had separate ambers at one point long ago that would likely have run off it. Gotta think, emergency flashing(like doing plow work) or just trailering(this did a lot of that) is a lot of load on stock setup. There used to be a light just like the one pictured on driver side but i broke it off and actually moved one of my cheap LED fogs(Up front) that is more like a spotlight and put it there for funsies last night. still need to rewire.. its a mess.