VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1937-1945 Another wiring question

While reading my Wiring Diagram for my 1940 Chevrolet, I noticed one strange thing. Is it possible that the Ignition Lock only switches the power on and off from the coil and the gas gauge? Am I missing something? Are all other circuits live with the key OFF? I understand that this would work, but it is it how they intended it? or do I have a WRONG diagram?

Thanks guys...

That is correct. The other things that would be connected to that post would be accessories such as a radio and heater,

Well, since my ignition switch has one exposed terminal, Power in, I can't connect anything else to be switched. The other side of the switch, to coil, is shielded. Now, I don't even know where to connect the gas gauge wire. I did buy an NOS wiring harness and not sure how the fuel gauge get connected , YET. I am still looking at it.

That seems strange, I would hook the gas gauge wire to the amp meter.

Ed,

Seems that there should be two posts. One is HOT all the time and the other is COLD except when the switch is turned on. The latter is then HOT too, along with the wire to the coil inside the shielded cable.

In other words, when the switch is ON then both posts are HOT on the back of the switch. When the switch is off, then the shielded wire is COLD along with one post on the switch.

The light switch uses a hot wire from the ignition switch's HOT post. I think. That and all other things that are usually HOT all the time, i.e., to some accessory switches, etc. This latter may be at the owners option as to whether he wants certain accessory options hot all the time,i.e., radio is a good one to consider.

Am I missing something here?

Anyway, I hope you get it straightened out soon. These things can be a bugger sometimes.
Charlie

BTW: Accessories switches can be run off anything that is hot all the time. Such as the heater and defroster switches, etc. They may be run off a hot post on the light switch. I like to leave them cold so if I fail to turn them off they won't run the battery down. Individual owner's call.

As much as it pains me to say so I agree with Charlie. Your switch won't work at all if you don't have the hot feed lug that connects to the ammeter. That's the lug to which you connect the full time powered accessories. You'll then have the switched hot that feeds the ignition and the armored cable to the coil.

A major consideration in which "hot" post to hook wires to is the amperage capacity of the ignition switch. If the current draw exceeds the capacity of the switch you risk destroying the ignition switch or having the heat (and resulting fire) destroy something else, like the whole car.

That reminds me of a question I've been wanting to ask but keep forgetting. If I connect an accessory to the unswitched side of the ignition switch, is there current going through the switch when I turn that accessory on? For example if I connect a cigarette lighter to the unswitched lug on the ignition switch, does it put a high draw on the switch when I operate the lighter without the switch being turned on? I would think there would be no current actually passing through the switch since it's on the feed side of the switch but I could be wrong.

You are correct in that no current is passing through the switch. I personally would connect any accessories that you want "hot" all the time to the amp-meter. Really no reason to connect to the ignition switch.

Unless you're a fat old man who can reach the back of the ignition switch easier (not having to crawl under the dash).

Easy fix on this one Tiny...Stop smoking...Then you don't need a cigarette/cigar lighter in your car...I smoked for 51 years and stopped 1 year ago, now I feel like I am 10 years younger..Maybe I will start jogging again. I use to jog but I had to quit..I kept dropping my cigarette and spilling my beer...Good Luck..ED

Haven't smoked in 40 years. I quit cold turkey in the fall of '82. I did put a cat eye lighter in the car though. It's kind of fun to show it off on occasion.

Ok Ed this is really important! Get one of those Lifeline badges with the panic button. I use it when I get pinned under the dash of my old chevy (working on ignition switch and cigarette lighter)
FYI it also works when you are walking back to the house after running out of gas because your fuel gauge is wired backwards and you fall and can't reach your beer...."I have fallen and I can't reach my beer! come quick!"

If you quit smoking in the fall of '82 that would be 30 years, not 40 years.

What's a Decade here or there.

Come on, give the fat kid a break. I never claimed to be good at math.

Tiny...What in "the name of Betsey" (As Charlie would say) is that brown raggedy thing hanging down from your rear view mirror area???? That looks like my late/great Grand mothers "DISHRAG" ...all grandmothers (as you know) had one of these and they could snap that thing and hit you on the ear every time while you were running at full speed though the kitchen...Grandmothers had a way of getting respect and love at the same time "Bless their hearts"...Makes me want to ring my hands and think of my Grandmother.
I loved her dearly.........ED

Eastern ED,

What you got right there is a garlic bag. Keeps vampires away. Works too!

Charlie

Ed, those are a pair of knitted cowboy boots my mom made when I was a pup. She passed 11 years ago and I use them as a mirror hanger to keep her a bit closer to me. Sure beats fuzzy dice.

As Bob Hope always said !
THANKS FOR THE MEMORYS...

Amen to that. Hey, Happy Birthday by the way.