Hi,
I own a 1951 Desoto Custom.I have never been able to get the car srarted.I charged the new 6 v battery to 2 on my battery charger. Installed it.Battery cable attached to the block on the pos.side and neg cable via starter............still nothing,not even lights.
Thanks,
Eric

Eric, let's back up. No lights? The wire that feeds the lights should be on the BATTERY SIDE of your starter relay. Troubleshoot this circuit FIRST.

From the starter realy, a constant 'hot' wire feeds your headlight switch, then your key switch. Did you rewire the starter relay or headlight switch?

What happens when you jump across the starter relay with heavy cables? Will the starter motor turn? If it does, check for power at the key switch and headlight switch, and follow it through the firewall to the starter relay. If it doesn't, you have bad battery connections, or bad battery cables.

Check your grounds, check your grounds, then check your grounds. I run my battery ground cable to the closest bolt to the starter motor, on the engine. Then, I run a separate wire from my battery ground to the car body. Notice, I ground the engine and body separately, starting from the battery. You don't have to, but I run yet another #4 copper ground through the body, all the way to the trunk. I tap off for the headlights (parking lights, voltage regulator, etc,), then I tap off for things under the dash, (radio, etc.), then I tap off all the lights in the trunk AND the fuel tank.

I don't depend on rust or spot welded sheetmetal to carry any electricity. Hope this helps. Dave

i put a 800 cca and 2 gauge wires to mine and it made a big differnce.and i still got to ground the body but havent got there yet. i found the battery at batteries plus, they had the highest ccas