The Stovebolt Site Forums The Shop Area The Electrical Bay Wiring Harness Instructions

I'm nearly finished wiring my '49 GMC 1/2T pickup and now that I'm at the fuse block I find that following the wiring instructions included with the 12-volt harness (seller unnamed), such as wiring the horn button to a hot circuit (there's no mention at all of the relay), would make a lot of trouble. So I've had to switch things. They may not be chapter and verse, but they'll work. Has anybody else had to modify the written steps? What are the best books or manuals for getting things right?

I can't answer your question about a book but the instructions with my YNZ's harness were Tiny proof. Clear and accurate. A lot of folks have good luck with low price harnesses but I believe you usually get what you pay for. If you already know where everything goes you're probably OK with the cheap harness.

Since it has a fuse block I assume it is a universal type harness and not an aftermarket made specifically for the truck.

I imagine the fuse block has a built in horn relay. The wire to the horn button would be a ground wire, not a "hot circuit". You won't need your original relay. There should be a wire from the fuse box directly to the horn.

Retread,

I am not sure if a true "how to wire" book exists. There are standard wiring practices that apply to most situations.

These would include fuses for protection, wire capacity for the intended load etc.

It appears you have your harness almost in, so your feet are already wet, so to speak.

I have enclosed a link to Chevrolet wiring diagrams. It shows how Detroit did it.

I would take a piece of paper and make a list of all the questions I had about my wiring so far.

Attack them one at a time, doing some research and looking at factory schematics to see how the factory addressed them.

It sounds like you were aware of the lack of a horn relay...this would not be obvious to everyone.

This forum is always here to answer your question or to confuse you more, which I usually have a hand in!

http://chevy.tocmp.com/chevywiring/

Stuart

Do any of the aftermarket harnesses include the wire that goes up the mast to the horn button assembly? Since it is a single wire to a connector, I wouldn't think so. The wire going up the mast does have V+ on it through the horn or through the relay, if so equipped, until the button is depressed, suppying ground to the wire.

I'm not aware of any. My mast jacket bushing came with the wire attached.

Thanks for the good sense.
I ended up going through a lot of past threads here on the Bolt and mudding through. Jack Sweeden's "How to Wire Your Streetrod" helped. Believe it or not, this one's just about ready to fire up.
Part of the problem was that the harness came with a bunch of splayed out different-length wires from two directions with connectors to where a fuse box would go. They didn't match to any box I could find. And the connectors were too big. I ended up cutting and splicing the wires to connect to a standard fuse box. I wonder why the harness-maker didn't just leave foot-long or so unfinished leads to connect to the box?
Anyway, it gave me something to cuss at when things seemed to be going too easy.