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1940 chevy, battery fully charged, cables good, clean and tight - won't turn over, no headlights, no horn, no electrical power period. I'm stumped!!!!

Reverse polarity issue? Fuse I can't find? Started and Ran fine 2 months ago, recently charged battery 3 weeks ago and checked today - reading 6 volts on Multimeter.

Thanks in advance for your help!!!!!

Probably something simple--did you merely inspect the battery cables at the posts, or did you remove and clean; could even be simple corrosion on the battery posts (which you can't see)--especially since you're not even getting power to the headlights. I'd try that first--I've lost power this way and after merely moving the cable clamps restored it.

Also if you have clamp on terminal ends. loosen and pull the wire out to clean. They build much corrosion there.

Do you have a battery shut off switch?

Check the fuse on your light switch. Looking at the wiring diagram it looks to be the main fuse. It's on the ammeter on my '38.

Excellent suggestions! I went back at it;

Checked fuse at headlight switch - Good

Checked Battery - Good

Checked voltage at Ammeter connection under dash - ~1 volt measured

Checked voltage at starter - ~2 volts

Removed Battery cable/switch, removed switch and installed battery cable without switch - PROBLEM SOLVED!!!!! FAULTY SWITCH.

Thanks again everyone!!

Glad to hear it was something simple. I suggest you replace the cut off switch for safety purposes.

I'm thinking of not using another cut off switch at the Battery. Perhaps a switch under the dash before the Ammeter is a better option, less chance of corrosion?

Speaking to many other classic car owners, not many bother with them anymore.

Thanks, Steve.

Hi Steve,

I suggest that you consider putting the switch just beyond the starter. That way there will be no electrical power to the any of the behind-the-dash area or anything else under the hood.

I also have to wonder if the cutoff switch failed because it was intended for a 12 volt system. The higher amperage of the 6 volt starter could have overheated the contacts.

That is exactly what he was describing, to put the disconnect after the starter, but before it goes into the ammeter.

Is this the best place to put a disconnect?

My pickup is currently wired incorrectly and I want to wire it properly and have a disconnect.

Is it recommended to put the disconnect between the starter and ammeter can someone say?

Extra Credit: what size wire would be used to run to the ammeter? I may need to make a new one, so wanted to check on wire size, I'll hopefully crimp ends onto it. I need to understand if I can use the old connector, get a new one, etc...but what is the proper size wire? (56-62 235 w/high compression is what I have in mine)

I think the wire size should be the same most likely on my pickup and his '40.

Alan

I put my disconnect switch on the ground (earth) side.

Hmmm...mine is like that, kinda sorta...

Mine goes Battery Negative -> Disconnect -> Engine Block.

Seems I should go Battery Negative -> body/chassis, then to disconnect even if I was to keep it like that.

EDIT: No, this above statement was wrong, I think going from battery negative post to disconnect is correct. On pondering this I think I just need a ground wire going from the disconnect out to the body/chassis ground.

Is positive the better place to run the disconnect?

Alan