3 Prong Power Cord Install???

[Phil_S]

You're almost there.

The green wire for the a/c service gets it's own chassis bolt. Move it off the circuit ground. I'm not an electrician, but I've been led to understand that what you did there doesn't meet code for appliance wiring. I think, if you should have a back feed you don't want it charging up the other stuff on that bolt.

Shorten up that green wire and ground it on a dedicated bolt near where it enters the chassis. If you don't want to drill a hole for a bolt, the nearest power transformer bolt would be my second choice.

[Structo]

Yes, it should go to a ground lug, that is mechanically fastened under the transformer nut with a star washer on top of it then the nut.

[lakehaus]

Here's what I did, and I haven't had a chance to check it yet (amp is disassembled for re-tolexing):

BTW - I did this before I saw all the helpful posts...

Removed old 2 prong cord
Used new 16g 3 wire cord
Soldered white lead to where the old white lead was (fuse)
Soldered black lead to where the old black lead was (switch)
Connected green lead to xformer post nut (the one mid-right in photo above in earlier post)

I did not remove death cap... maybe I should???

I plugged it in - turned on the amp, power light came on. There are currently no tubes or speaker hooked up.

Critique please... but layman's terms as I'm no tech.

[Structo]

Yes absolutely take the death cap out.

I can't remember if this amp has a ground switch?

[lakehaus]

Yes absolutely take the death cap out.

I can't remember if this amp has a ground switch?

It's just a matter of desoldering the death cap, right?

I have no idea if this amp has a ground switch. I have several pics that you can scan thru - some of the chassis / guts are very high rez.

Open pics here

[Structo]

No it doesn't have a ground switch.

Just unsolder the death cap from the fuse holder and chassis.

[Phil_S]

You might consider leaving a hanger on the chassis that you can solder something onto in case you need it. Don't clip the death cap flush, leave a piece of lead there for future use. You never know. It takes a 100W soldering gun to attach something to the chassis and that kind of heat is dangerous (to the amp) in untrained hands.

[drew]

Removed old 2 prong cord
Used new 16g 3 wire cord
Soldered white lead to where the old white lead was (fuse)
Soldered black lead to where the old black lead was (switch)

Isn't the black lead in the new cord the hot one, and the one that should be going to the fuse? (Note that I am asking, not asserting . . . experts, please weigh in.)

[Structo]

Isn't that what he did?

OK -
Green ground wire to filter cap ground.
Hot black wire to center of fuse. Black side of fuse to switch, black from switch to PT.
Neutral white to PT.
Hopefully you can see it all from my pictures.

[drew]

If I'm following this correctly, the thread was started by lakehaus. Hired hand's post that you quoted was advising lakehaus how to do what he asked about. Lakehaus' subsequent post, which I quoted, seems to indicate that he did the opposite of what hired hand advised, with regard to the hot and neutral leads.

[Structo]

Sorry my bad.

I didn't realize there were two guys doing a similar thing.

[C Moore]

Sorry my bad.

I didn't realize there were two guys doing a similar thing.

No actually it is "my bad" for confusing things. And I am also man enough to say I fixed my crappy ground connections per the advice of some of the prior posts. I still have a lot to learn.
Thank You Gentlemen

[lakehaus]

What I did before I read any responses was duplicate white to white, black to black, then grounded green to chassis at the xformer bolt.

Then I saw the responses suggesting I do the opposite of what I did!

So, to be clear - and to help this novice understand - here's what I SHOULD DO to my '70 VIBRO CHAMP:

Black from the new 3 prong cord goes to the fuse? That's where the old white wire from the orig 2 prong cord went.

White from the new 3 prong cord goes to the switch? That's where the old black wire from the orig 2 prong cord went.

Ground the green wire from the new 3 prong cord to the chassis at the transformer bolt.

I have not clipped the death cap yet, but fully intend to... right?

I did plug it in and turned on the switch. The power light came on, but I didn't plug in my guitar (tubes were removed, speaker unplugged at the time while cab is being retolex'd).

Pics below.

______________________________________________
This is before (light and power switch disengaged from chassis during faceplate removal):

[img680]http://i256.photobucket.com/albums/hh17 ... htBack.jpg[/img]

This is after:

[img:640:480]http://i256.photobucket.com/albums/hh17 ... G_0116.jpg[/img]

[Structo]

The cords black wire should go to the fuse, from the fuse to the switch.
The white wire should go to the primary and the wire from the switch should connect to the other primary wire.

The reason you want the fuse on the hot side (black) is so if it blows the hot wire is out of circuit.
You always want the switch on the hot (black) leg.

[lakehaus]

The cords black wire should go to the fuse, from the fuse to the switch.
The white wire should go to the primary and the wire from the switch should connect to the other primary wire.

The reason you want the fuse on the hot side (black) is so if it blows the hot wire is out of circuit.
You always want the switch on the hot (black) leg.

Thanks Structo... looking at the pics in my last post, which wire is the primary? Sorry, and pardon my ignorance - I'm new to this stuff, but willing to learn!