I have a 1950 F1 and the battery needs replaced. I have read good things about Optima 6 volt batteries. When you check the Optima site it says the Optima battery doesn't fit the 1950 F1 and you need to make it fit. The battery now is 10" long, 6 3/4" wide, and 7.5 " deep. The Optima is 10" long (9 7/8" on top), 3.5" wide and 8 1/4" deep. Optima has these plastic pieces they offer. Is that all that is needed? Please describe what you do to secure the battery. Pictures welcome. My battery is negative ground and it seems like other old Fords are positive ground. Is that a problem or what do I do? Thanks, Paul

 

Let's define our terms first. That doesn't make any sense. Your truck is negative ground? Or positive ground? The battery is just a battery.

It's more likely, that the truck is 12 volts if it has been previously converted to negative ground. A 1950 Ford was originally 6 volts, positive ground.

 

The bare (I assume ground) cable is attached to the negative pole of the battery. The battery is 6 volt--3 cells, I charged it with the charger set to 6 volts.

 

Seems like a goofy question but did your truck run before the battery went bad? If so just drop the optima in and go. There should be clearance for the larger battery. My 12 volt optima came with plastic pieces for modifying the battery mounts. Be sure to use some type of battery hold down. Our batteries are in a bad location for a quick battery disconnect if something goes wrong. Especially while cruising.

 

Everything except the coil and generator won't care if you switch the battery cables. Your truck should be positive ground. That could be why your battery is dead, the generator can't recharge it.

 

Thanks for your comments. The truck had a near complete rebuild more than 10 years ago. The current battery is about 5 or 6 years old and the truck has only about 60 miles on it since rebuild and battery was not regularly charged--I have been surprised it keeps enough charge from a charger to start it. Truck runs fine now but battery only takes about 60-70% of a charge using a 6 volt charger and battery doesn't stay strong long. I have only had the truck for a week and put less than 10 miles on it so I will see what my father in law recalls. It seems like I saw that some old trucks have been changed over to negative ground but I will have to check on that--possibly they did that with the rebuild. (Or they just put the battery in backwards after the rebuild and it hasn't been driven enough to see that it wasn't charging from the generator). Thanks again for any thoughts.

 

Just some more information--I spoke with my in law and he says it was negative ground as long as recalls (he had it since the 80's) and was negative ground when he put the current battery in 5 or 6 years ago. He theorized his uncle the original owner from 1950 until the 80s was a master mechanic so he may have switched it to negative ground. I think the truck was bought in USA originally although possible it was bought in Canada if that would make a difference. Finally, the truck has a battery gauge and it has appeared normal when the truck is running (moves a little to the right of center toward charge)--wouldn't the battery gauge be showing discharge or something weird if in fact the battery was just put in backwards? Thanks again.

 

It would be pointless to change from 6v (+) ground to 6v (-) ground. Changing from 6v (+) ground to 12v (-) ground is very common.

 

I have my '54 negative ground. I thought for towing my trailers I want them to match up with the way they were wired. I just put 6 volt bulbs in the trailers when I use them. Dennis

I also have a '55 fairlane that was negative ground when I bought it in 1984. I switched the battery cables and repolarized the generator. Been good ever since.

 

I find it hard to believe anyone would actually perform the required mutilation to both battery cables to switch from positive to negative ground.

 

What mutilation is required? My battery cable ends spread enough to switch posts. I should have mentioned 2 of my trailers have 12 volt batteries to operate the brakes. Dennis

 

Switching grounds: There is a school of thought out there that positive ground causes more corrosion. The below is a modern statement of it but it seems to go back a number of years. See page 218:
https://books.google.com/books?id=Ao...ground&f=false
Some have said the US Navy uses negative ground in ships as it helps with cathodic protection. There certainly are contrary views that negative ground has no advantage other than uniformity but there was at least some basis to switch an old Ford to negative ground even when keeping it 6 volt--if that's what my wife's late uncle did to the truck 25 or more years ago.

 

Well, OK. I only brought it up here, so everybody is on the same page. 6 volts, 12 volts, negative ground, positive ground, need to know.

The starter doesn't care either way, it will still spin the right direction. And a 6 volt starter spins happily with 12 volts. My brain hurts already thinking about it. Have to polarize the generator, in order for it to charge. I think the gauges would read backwards though?

For all that if it were me keeping it 6 volts, or even converting to 12, there are plenty of good batteries other than Optima. They even look funky in an old Ford. Maybe that's not a real thing, but to me it looks alien under the hood or wherever.

 

Ross,
What happens to the 6 v. regulator when you go to 6 v. (-) ground even if you polarize the 6 v. generator? I wouldn't think the regulator would work correctly. Be nice to know if 50Red's generator is charging after all the smoke clears.
TractormanBill

 

I've always had that question. Apparently they work OK, although I can't see how. The coils in the regulator relays would seem to have opposite current flow, so that their magnetic field would also be backwards and not pull in the relay points.